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No. & Date AskedQuestion
# 2 :: 10/23/07
Question 2 has been Answered
Joe received a z score of -1.50 on a classroom test. This means that, compared to his classmates, Joe's score was...?. . .

Z-Score, 1.5, lambda

# 3 :: 10/23/07
Question 3 has been Answered
What is the critical z score for a one tailed test with alpha = .01.. . .

Alpha, Z-Score

# 4 :: 10/23/07
Question 4 has been Answered
Where can I find a Z score chart ?. . .

Z-Score

# 5 :: 10/23/07
Question 5 has been Answered
If you have a normal distribution of a random variable x, with a mean of 56 and standard deviation of 8: What is the probability that the random varia. . .

Nomal Distribution, Normal Curve

# 6 :: 10/23/07
Question 6 has been Answered
How do you determine the sample size for data for which the mean and standard deviation are not known?. . .

Standard Deviation, Sample Size, Margin of Error

# 9 :: 10/23/07
Question 9 has been Answered
How do you make data normally distributed?. . .

Transformation, Log Transformation, Monte-Carlo, Bootstrap, Non-Normal Data, Normal Distribution, Non-Parametric

# 10 :: 10/23/07
Question 10 has been Answered
What is the difference between a Z-Scores and Process Sigma?. . .

Process Sigma, Z-Score, 1.5 Sigma Shift

# 11 :: 10/23/07
Question 11 has been Answered
What is the z value for 1.648?. . .

Z-Score

# 12 :: 10/23/07
Question 12 has been Answered
Can a z score be calculated by input of a proportion only?. . .

Proportion, Z-Score

# 13 :: 10/23/07
Question 13 has been Answered
How unusual is this event (Z-Score)? A department store, on average, has daily sales of $28,707.47. The standard deviation of sales is $1000. . . .

Z-Score, Unusual Event

# 14 :: 10/23/07
Question 14 has been Answered
What percent of the time should this occur? (Z-Score) ?. . .

Z-Score, Normally Distributed, Standard Deviation, Normal Curve

# 15 :: 10/23/07
Question 15 has been Answered
How do you calculate a Z-score with a two-sided specification limit? What is the DPMO?
I have a lower spec limit of -0.008 and an uppers spec lim. . .

DPMO, Z-Score, Process Sigma, Z-upper

# 16 :: 10/23/07
Question 16 has been Answered
What is the Trimmed Mean For?. . .

Trimmed Mean, Task Time

# 17 :: 10/29/07
Question 17 has been Answered
Having obtained the z score and then derived the percentage... what does the percentage tell you?. . .

Unusual Event, Z-Score

# 18 :: 10/29/07
What is sample variance?. . .

# 19 :: 10/29/07
Question 19 has been Answered
Does a sigma value relate the voice of the process to the voice of the customer?. . .

QFD

# 20 :: 10/29/07
I want to know why we call six sigma statistically , i mean how six sigma is 50% of tolerance. . .

# 21 :: 10/29/07
Question 21 has been Answered
How do you calculate standard deviation?. . .

Standard Deviation

# 22 :: 10/29/07
Question 22 has been Answered
How do you standardize the height of a 10-yr old boy of 134.2cm ?. . .

Standardize

# 23 :: 10/29/07
How do you calculate z-score for x-bar 2.7,u=3,s=1 and n=100 ?. . .

# 24 :: 10/29/07
Question 24 has been Answered
Using the standard normal table, the total probability to the right of z=2.18 and to the left of z=1.75 is?. . .

Normal Table, One-Tailed Area, One-Sided Area

# 25 :: 10/29/07
Question 25 has been Answered
What does a Z-score look like on a graph?. . .

Z-Score

# 26 :: 10/29/07
Question 26 has been Answered
How do you calculate z-scores from batting averages?. . .

Z-Score

# 27 :: 10/29/07
Question 27 has been Answered
What does percentile rank mean?. . .

Percentile, Percentile Rank

# 28 :: 10/29/07
Question 28 has been Answered
What is one of the two differences between the way ZST or ZLT are calculated?. . .

Z Short Term, Z Long Term

# 29 :: 10/29/07
Question 29 has been Answered
How do you calculate a z-score on discrete data?. . .

Z-Score, Discrete Data

# 30 :: 10/29/07
How is a z score measured?. . .

# 31 :: 10/29/07
Question 31 has been Answered
What is the Z score of a 98% confidence interval?. . .

Confidence Intervals, Confidence Level

# 32 :: 10/29/07
What proportion is Less than 52. With mean of 67.56 and standard deviation of 25.7. . .

# 33 :: 10/29/07
Question 33 has been Answered
How do you find a z score such that 8% of the area under the curve is to the right of Z?. . .

Z-Score, One-Sided Area

# 34 :: 10/29/07
How do you get a Z score from a standard deviation?. . .

# 35 :: 10/29/07
Question 35 has been Answered
Can you please explain the 1.5 sigma shift they use in determining process sigma?. . .

1.5 Sigma Shift

# 36 :: 10/29/07
What is the formula for finding the z score for a population ?. . .

# 37 :: 10/29/07
Question 37 has been Answered
How do you calculate the z score for the raw score of 10 based on the following distribution: 8, 9, 15, 30, 7, 8 ?. . .

Z-Score, Standard Deviation

# 38 :: 10/29/07
Question 38 has been Answered
Alexa got 144 on her test which has a mean of 128 and a standard deviation of 34. What is her z-score?. . .

Z-Score, example

# 39 :: 10/29/07
Question 39 has been Answered
What is the basic formula for the z-score other than table of areas?. . .

Newton-Raphson, Z-Score

# 40 :: 10/29/07
Question 40 has been Answered
What are the properties of the z-score in data analysis?. . .

# 41 :: 10/29/07
Question 41 has been Answered
On a scale from 0 to 100, the mean level of economic development among the countries in the world is 65 and the standard deviation is 10. What proport. . .

Z-Score, Standard Normal Curve

# 42 :: 10/29/07
Question 42 has been Answered
What are the units of z-score?. . .

Z-Score, Units of Measure

# 43 :: 10/29/07
Question 43 has been Answered
What is the Z-score formula for EXCEL?. . .

Excel

# 44 :: 10/29/07
Can you get a z score for both a sample and a population?. . .

# 45 :: 10/29/07
Question 45 has been Answered
How do you standardize data?. . .

Standardize

# 46 :: 10/29/07
Question 46 has been Answered
How to calculate a Z-value for Altman's Bankruptcy Formula?. . .

Altman Z-Score

# 47 :: 10/29/07
Calculate the z score for a raw score of 10 from the folowing scores:10,20,25,5,30. Based on your anser ,approximately what percentile does the raw sc. . .

# 48 :: 10/29/07
Question 48 has been Answered
Suppose that the scores of architects on a particular creativity test are normally distributed. What percentage of architects have Z scores? a. above . . .

Z-Score

# 49 :: 10/29/07
Question 49 has been Answered
How do you calculate T scores?. . .

# 50 :: 10/29/07
What is the DPMO calculation for a discrete task?. . .

# 51 :: 10/29/07
Question 51 has been Answered
How do you get x bar?. . .

# 52 :: 10/29/07
What is the z score for 10?. . .

# 53 :: 10/29/07
Can you have a negative z-score?. . .

# 54 :: 10/29/07
What is the actual formula for finding the exact probability from the z-score without having to use the table?. . .

# 55 :: 10/29/07
How do you interpret a z-score?. . .

# 56 :: 10/29/07
It seems the normal distribution function in excel requires more arguments than specified in this article.. . .

# 57 :: 10/29/07
Question 57 has been Answered
In order to calculate dpmo, why do you need multiply 1 million?. . .

DPMO

# 58 :: 10/29/07
Question 58 has been Answered
Why don't statisticians calculate 100% confidence intervals?. . .

Confidence Intervals, Confidence Level

# 59 :: 10/29/07
How could we rescreen for defective units from a population of 900 units and establish a 95% confidence that the whole 900 units are acceptable.? How . . .

# 60 :: 10/29/07
How do you calculate asymmetric confidence intervals?. . .

# 61 :: 10/29/07
Question 61 has been Answered
What is the connection between the confidence level and the confidence interval?. . .

# 62 :: 10/29/07
If I had 6600 wigets, how many do I have to test with 0 failures to show 95% of them are acceptable with a 95% confidence?. . .

# 63 :: 10/29/07
How do you compare confidence levels?. . .

# 64 :: 10/29/07
On what method is the Excel based calculator that you have provided based on (Exact, Score, Wald, Adjusted Wald). Also, what method is the calculation. . .

# 65 :: 10/31/07
Question 65 has been Answered
If a standard deviation of a set of data is zero, what can you conclude about the set of values?. . .

# 66 :: 11/6/07
Question 66 has been Answered
The probability that Luis will pass his statistics test is 0.44. What is the probability that he will fail his statistics test?. . .

# 67 :: 11/6/07
Question 67 has been Answered
Among the contestants in a competition are 35 women and 20 men. If 5 winners are randomly selected, what is the probability that they are all men?. . .

# 70 :: 12/10/07
Question 70 has been Answered
The grades on the midterm given in a large managerial stats class are normally distibuted with mean 75 and standard deviation 9. Instructors of this c. . .

Z-Score, Percentile

# 75 :: 1/20/08
Question 75 has been Answered
Students given exam with 300 multiple questions, distribution was normal and mean 195 with a standard deviation of 30. What were the scores of the st. . .

# 76 :: 1/20/08
Question 76 has been Answered
How do you use the spss table?. . .

# 77 :: 1/22/08
Question 77 has been Answered
How should I compute probability in spss for variable "seizure duration" with unnormal distribution which constitutes numerical data of duration in se. . .

# 78 :: 1/23/08
Question 78 has been Answered
What does measuring the standard deviation of a set of data tell you about the data. . .

# 79 :: 2/4/08
Question 79 has been Answered
How do you figure the individual X value of interest. . .

# 80 :: 2/4/08
Question 80 has been Answered
How do you determine percentage of brackets (that hold struts) created with misaligned holes? What is a calculation in determining a percentage of bra. . .

# 81 :: 2/10/08
Question 81 has been Answered
calculate the z score of 9o th percentile?. . .

# 82 :: 2/14/08
Question 82 has been Answered
In a previous study, drug X had a side effect that is seen 50% in women and %80 in men. Howmany patients must be included in a new study (0.80 (beta) . . .

# 83 :: 2/18/08
Question 83 has been Answered
Dear Jeff Sauro, We found your website very interesting, and were hoping that you could provide some insight into a question we have concerning a pot. . .

# 84 :: 2/19/08
Question 84 has been Answered
If you record data for a year, and find that the mean number of women in shelters is 250, with a standard deviation of 75, and the distribution is nor. . .

# 86 :: 2/19/08
Question 86 has been Answered
For a standard normal curve, whats the z-score that corresponds to the third quartile . . .

# 88 :: 2/20/08
How do you calculate the standard deviation from the confidence interval?. . .

# 89 :: 2/22/08
Question 89 has been Answered
Where is using the t statistic an appropriate alternative to using a z-score?. . .

# 90 :: 2/23/08
Question 90 has been Answered
The cholesterol levels of a population have a normal distribution with a mean of 160 and a standard deviation of 30 how you I find the percentage of t. . .

# 91 :: 2/24/08
Question 91 has been Answered
IQ tests generally have scores in which the mean is 100, and the standard deviation is 16. If your IQ score was 134, what percentage of the population. . .

Normal Curve

# 92 :: 2/28/08
Question 92 has been Answered
Which has the tighter spec limits, 3 sigma or 6 sigma?. . .

# 93 :: 2/29/08
Question 93 has been Answered
I have two contingency tables. One has a chi-square value of 14.40 and the other is 27.86. Both have 6 degrees of freedom. Based on an alpha of .01. . .

# 94 :: 2/29/08
Question 94 has been Answered
In one town, 36% of all voters are Democrats. If two voters are randomly selected for a survey, find the probability that they are both Democrats.. . .

# 96 :: 3/1/08
Question 96 has been Answered
The mean is = 60.0 and the standard deviation is = 4.0. Find the probability that X is less than 53.0.. . .

Z-Score

# 97 :: 3/1/08
Question 97 has been Answered
A medical school claims that more than 28% of its students plan to go into general practice. It is found that among a random sample of 130 of the scho. . .

Normal Approximation to Binomial , BINOMDIST, Continuity Correction, 1-Sample Proportion Test, 1-Proportion Test

# 98 :: 3/1/08
Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your finding to state whether or not the . . .

# 99 :: 3/2/08
what is the mean of the z score. . .

# 100 :: 3/3/08
i am trying to figure out the best means to calculate the reliabilty of our work load index ie a measure of work load per empolyee per hour - is there. . .

# 101 :: 3/3/08
When is using the t statistic a more appropriate alternative to using a z-score? . . .

# 102 :: 3/3/08
How can a t test be employed in hypothesis testing by the use of directional vs. nondirectional hypotheses?. . .

# 103 :: 3/9/08
What is the Standard Deviation of a z-score?. . .

# 104 :: 3/9/08
Trimmed mean, 80% trimmed mean = ? was a question on a homework assignment. When I read my notes the teacher had written 10 values, then eliminat. . .

# 105 :: 3/10/08
Question 105 has been Answered
For large correlations, the SAS program simply states that p < .0001. But to conduct a meta-analysis I need to know the exact p values for large corr. . .

# 106 :: 3/10/08
suppose that the scores of architects on a particular creativity test are normally distributed. What percentage of architects have Z scores?. . .

# 107 :: 3/10/08
Suppose a candidate running for sheriff claims that she will reduce the average of emergency response to less than 30 minutes. (30 minutes is thought. . .

# 108 :: 3/10/08
Compute a chi-square test for goodness of fit for each of the following, using the .05 level for each. In each problem, the expected distribution is . . .

# 109 :: 3/10/08
A director of a social agency is planning to hire temporaty staff to assist with intake. In making plans, the director needs to know whether there is. . .

# 110 :: 3/12/08
If I have unnormal data with n=15, and there are 2 samples. What test do I use? How do I make the data normal if the samples contain zero, b/c it's . . .

# 111 :: 3/12/08
Expected Project duration:25 days Probability for 27 days Standard deviation :5.656. . .

# 112 :: 3/13/08
getting the formular for confindence interval. . .

# 113 :: 3/16/08
How do you find the value of r?. . .

# 114 :: 3/16/08
Question 114 has been Answered
The mean on this test is 3.5 with a standard deviation of .5. Billy scores 5. What is the standard score?. . .

Standard Score, Z-Score

# 116 :: 3/18/08
Hi. I'm going to run a nested model in logistic regression. I have a dependent variable (nest) and I have two sexes (male/female). I can not run this. . .

# 117 :: 3/19/08
What is the significance of the picture at the top of the t-table? What is the difference between a sample parameter (X-bar and s) and a proportion pa. . .

# 119 :: 3/20/08
Question 119 has been Answered
Is is possible to modify a semantic differential scale into a 10-point scale? If so, should the data be treated as ordinal or interval? . . .

Bell Curve, ANOVA, Ordinal, Interval

# 120 :: 3/20/08
Question 120 has been Answered
What statistics test should I be using when I am assessing whether subjects were able to complete a task (i.e. Yes/No nominal data) before instruction. . .

# 121 :: 3/20/08
What is the differences among a proportion, a percentage, and a ratio?. . .

# 122 :: 3/20/08
When would you use a hypothesis test for the difference in two population proportions at your place of employment?. . .

# 123 :: 3/20/08
How does a non-parametric business scenario differ from a parametric business scenario?. . .

# 124 :: 3/20/08
Question 124 has been Answered
What constitutes a small sample size in a test of two populations? . . .

t-distribution, Z-Statistic, Small Sample

# 125 :: 3/20/08
Question 125 has been Answered
When testing two populations with small sample sizes, do both sample sizes have to be identical? Why or why not?. . .

Unequal Sample Size

# 126 :: 3/22/08
what is the distinction between a qualitative and a qualitative measure?. . .

# 127 :: 3/25/08
can anyone explain? Age so individuals in a certain population are normally distributed with a mean of 55 and standard deviation of 10 years. What age. . .

# 128 :: 3/25/08
Question 128 has been Answered
What is the value of z score required for a 70% confidence interval?. . .

Z-Score, , Confidence Intervals

# 129 :: 3/27/08
Hi when we have several criteria with different scale, for ranking can we add values after standardization? for exaample for ranking websites we have. . .

# 130 :: 3/28/08
Question 130 has been Answered
what is the value of 1sigma 2sigma 3sigma 4sigma 5sigma 6sigma. . .

Six Sigma

# 131 :: 3/29/08
which statistic technique can i use.. when i apply three treatment(treatment 1, treatment2, treatment3)on 2 dependent variable?(i applied 3 treatments. . .

# 132 :: 3/30/08
Question 132 has been Answered
why use 6sigma instead of 5 or 4sigma in calculating process capability. . .

Six Sigma, DPMO, Process Sigma, Sigma Level

# 133 :: 3/31/08
When number of Passed is half of total Tested, why all points estimates are 0.50. Tk. . .

Standard Score

# 135 :: 3/31/08
Question 135 has been Answered
I am conducting a ring test where 6 laboratories were asked to measure protein levels in the same flour sample. I then calculated the z score for each. . .

Z-Score

# 136 :: 4/4/08
Ran parts and found 1% defective(1 out of 100). Made a change to the process and want to rerun parts. How many parts do we need to check (and find 0% . . .

Process Sigma, DPMO

# 137 :: 4/4/08
Question 137 has been Answered
What score would Sandra need to beat 91 percent of her mathematics class? The mean score was 73, and the standard deviation was 12.. . .

Z-Score

# 138 :: 4/4/08
You can win $100 if you succeed in any one of the following: 1) draw a spade from a fresh deck of cards; 2) draw a heart from a fresh deck of cards; . . .

# 139 :: 4/6/08
how do you calculate the appropriate analysis. . .

# 140 :: 4/7/08
Question 140 has been Answered
Prediction of business failure using statistical methods. . .

# 141 :: 4/7/08
Question 141 has been Answered
whwn we say six sigma, does it mean six sigma on either side of the axis or is 3 sigma on either side. . .

Six Sigma

# 142 :: 4/7/08
Opposed to death penalty. Year 2000- 801 opposed out of 2565. Year 1993 337 opposed out of 1488. I have two samples, one is 31.2% and one is 22. . .

# 143 :: 4/7/08
Question 143 has been Answered
how to interpret the z- score. . .

# 144 :: 4/8/08
In a council election, 5 people are running, 3 seats available, and you want two for sure to win,but no caring who the third is. Should you only vote. . .

# 145 :: 4/8/08
Question 145 has been Answered
Will the t statistics calculated from 4 observations valid?. . .

t-statistic, t-distribution, Small Sample

# 146 :: 4/9/08
Question 146 has been Answered
what is the z-score that corresponds to the 20th percentile of the normal distribution. . .

Z-Score, Percentile

# 147 :: 4/12/08
Question 147 has been Answered
find the midrange for the given sample data. 1.5 2.5 3.0 1.2 1.3 3.8 1.8 3.3 2.3 2.9 1.8. . .

Mid-range

# 149 :: 4/14/08
Question 149 has been Answered
You are interested in whether men participate more than women in political activities, so you survey 632 men and 675 women and ask them how many polit. . .

2-sample t-test, t-statistic, t-test

# 150 :: 4/14/08
Exploitron, Inc. conducts a random survey of 700 of their workers and finds that the average employee earns $31,782 per year, with a standard deviatio. . .

# 151 :: 4/14/08
Question 151 has been Answered
A random sample of 25 households finds that an average of 2.3 people reside in each house (the standard deviation is 0.35). With a 95% confidence lev. . .

TINV, t-statistic, t-distribution, Confidence Intervals, Standard Error of the Mean, Margin of Error

# 152 :: 4/14/08
Question 152 has been Answered
If 350 respondents out of a random sample of 1,000 Americans reported that they did not trust their government, what is your estimation at a 99% confi. . .

Adjusted Wald, Confidence Intervals

# 153 :: 4/14/08
Question 153 has been Answered
You survey a sample of 10 college students to measure their racial prejudice using a scale of 0 (no prejudice) to 100 (extreme prejudice). Here are t. . .

skew, Median

# 154 :: 4/15/08
I can do the math in all of my Probability & Stats 101 questions, but I can't tell which formula to use for what question. How can I interpret the wor. . .

# 155 :: 4/16/08
Question 155 has been Answered
difference between a sample parameter ( X-bar and s ) and a proportion parameter ( p )? . . .

x-bar, Standard Deviation

# 156 :: 4/16/08
Could you please tell me in what situation the maentl hanszel test is more appropriate than using chi square. I believe maentl hanszel is used when a . . .

# 157 :: 4/17/08
Question 157 has been Answered
With a z score of 1.5, what percentage often scores are above 52 and what percentage of the scores are above 60?. . .

Z-Score

# 158 :: 4/18/08
Question 158 has been Answered
If I have a set of values(direct measurements of dynamic deformations of a road at 100m) between 3 and~1000, how can I calculate the 2 characteristica. . .

Monte-Carlo, Student-t, t-distribution

# 159 :: 4/18/08
Question 159 has been Answered
A parameter is a population characteristic. The numerical value of a parameter usually cannot be determined because we cannot measure all units in th. . .

# 160 :: 4/21/08
Question 160 has been Answered
in a sample of 1000 tv vieweres 330 watched a particlar programme. find 99 pecent confidence limits for tv viewers who watched this programme. . .

Confidence Intervals, Adjusted Wald

# 161 :: 4/21/08
Question 161 has been Answered
z Scores lenths are measured in centameters, does it have to be converted to a different unit of measurment? . . .

Z-Score

# 162 :: 4/22/08
Question 162 has been Answered
I am trying to do A/B testing onweb page displays. One is the test the other is the control. Could you help me determine the formula for sample size . . .

Confidence Intervals, Control Chart, A/B Testing, p-chart

# 163 :: 4/22/08
Question 163 has been Answered
When calculating confidence interval estimates...how is the x and standard deviation calculated?. . .

Standard Deviation, Confidence Intervals

# 164 :: 4/23/08
Question 164 has been Answered
how to calculate one sided 95% confidence limits for a proportion.could you provide a formula . . .

Adjusted Wald, Confidence Intervals, One-Tailed Area

# 166 :: 4/23/08
Question 166 has been Answered
What is the equation to go from a Z-score to a percent? I know how to use the table but i want to know the actual formula/equation.. . .

Newton-Raphson

# 167 :: 4/24/08
Question 167 has been Answered
I know that 33 is the raw score of the 85th percentile. How do I determine the mean?. . .

Percentile, Standard Deviation

# 169 :: 4/25/08
Question 169 has been Answered
Various temperature measurements are recorded at different times for a particular city. The mean of 25C is obtained for 60 temperatures on 60 differen. . .

Null Hypothesis , Alternative Hypothesis , t-statistic, Z-Statistic, 1-sample t-test

# 170 :: 4/25/08
Question 170 has been Answered
If last six month average defect rate is 5% then what will be the process Zst score? . . .

1.5 Sigma Shift, Z-Score, Z Short Term

# 172 :: 4/27/08
Question 172 has been Answered
The library is to be given 3 books as a gift. The books will be selected from a list of 18 titles. If each book selected must have a different title, . . .

Choose, Combination

# 173 :: 4/27/08
Question 173 has been Answered
why can you not have a z- score equaling 0/0 ? what is problematic with calcutlating a z-score for a data set of repeated entries?. . .

Z-Score

# 175 :: 4/28/08
Question 175 has been Answered
Suppose that in NY State, 35% of voters are Democrats, 30% are Republicans, and 11% are independent. You are conducting a poll by randomly calling reg. . .

Probability, Multiplication Rule, Binomial Probability, Choose, binomial, Binomial pmf, Binomial cdf

# 176 :: 4/30/08
Question 176 has been Answered
In a 0ne-tail test (l side) with z score of 1.645, what are the percentages for critical value and non-critical value?. . .

One-Tailed Area, Z-Score, Critical Value

# 177 :: 5/2/08
Question 177 has been Answered
Find the probability that a randomly selected adult has an IQ that is less than 130. . .

IQ Score, Z-Score

# 180 :: 5/5/08
Question 180 has been Answered
How to convert a exam score (standard score) back to Percent score? e.g. Total of students 16, 71 76 56 79 74 72 68 75 77 61 81 75 7. . .

Standard Score, Percentile, Percent Score

# 181 :: 5/5/08
Question 181 has been Answered
What is the difference between a population standard deviation and a sample standard deviation?. . .

Standard Deviation, Degrees of Freedom

# 182 :: 5/5/08
Question 182 has been Answered
When would you use a hypothesis test for the difference in two population proportions at your place of employment, in your education, or in politics?. . .

Hypothesis Test, Two-Proportion Test

# 183 :: 5/7/08
Question 183 has been Answered
I am trying to apply the problem discovery sample size formula to several finite populations. How should I integrate the finite population correction. . .

Problem Discovery, Finite Population

# 185 :: 5/7/08
Question 185 has been Answered
Hi I am performing a regression analysis with 3 x variables. My question is, if I have high p values (i.e. above 0.05) for each of the x coefficie. . .

Regression Analysis, collinearity, Correlation

# 186 :: 5/9/08
Question 186 has been Answered
how does altman build z-score? please send to my email the process of building this score!. . .

Altman Z-Score, Z-Score

# 188 :: 5/12/08
Question 188 has been Answered
How do I do a Chi-Square test on unequal sample sizes?. . .

Chi-Square, Unequal Sample Size

# 189 :: 5/12/08
Question 189 has been Answered
A sample of PVC pipes coming off a production line were tested for pipe diameter size. The statistical results (in millimeters) were: Mean 300 . . .

Normal Rule, Normal Curve, Bell Curve, Normal Distribution

# 190 :: 5/12/08
Question 190 has been Answered
200 people were sampled and the following table shows the number of people with a certain average electric energy usage based upon the type of home an. . .

Addition Rule, Mutual Exclusive

# 191 :: 5/12/08
Question 191 has been Answered
When would you use regression correlation at your place of employment, in your education, or in politics?. . .

# 193 :: 5/14/08
Question 193 has been Answered
How can I determine the sample size for data that is discrete but not binary?. . .

# 194 :: 5/14/08
Question 194 has been Answered
Why should you use ANOVA instead of several t tests to evaluate mean differences when an experiment consists of three or more treatment conditions?. . .

Bonferroni correction, ANOVA, Type I Error

# 195 :: 5/14/08
Question 195 has been Answered
Time/CNN voter polls monitored public opinion for the presidential candidates during the 2000 presidential election campaign. One Time/CNN poll conduc. . .

# 197 :: 5/15/08
Question 197 has been Answered
Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $45,000. Assum. . .

Normally Distributed, Standard Deviation, Margin of Error, Sample Size

# 198 :: 5/17/08
Question 198 has been Answered
Find the value of Z a/2 that corresponds to a level of confidence of 98.22 percent.. . .

# 199 :: 5/19/08
Question 199 has been Answered
A local bakery determines that the probability of a customer ordering a blueberry muffin is 50%. 5 customers come into the bakery. A. What is the pr. . .

Binomial Probability, binomial

# 200 :: 5/19/08
Question 200 has been Answered
I've calculated the confidence intervals about a regression line. My data is log transformed and has high R-square value for what is called "power" e. . .

# 201 :: 5/20/08
Question 201 has been Answered
Hi I am running a study comparing 3 different products on five different experimental visits. The same subjects are used for each visit and the same. . .

Counterbalance

# 202 :: 5/21/08
Question 202 has been Answered
Site preparation for new housing developments for tracts of 40 houses is normally distributed with a mean of 250 workdays and a standard deviation of . . .

Z-Score

# 203 :: 5/22/08
Question 203 has been Answered
How to determine the sample size for comparing mulltiple parameters like Height , weight, Blood pressure , Blood parameters like blood glucose, total. . .

Sample Size, Power, ANOVA, t-test

# 204 :: 5/22/08
Question 204 has been Answered
What does a z value mean?. . .

Z-Score, Z-value, Standard Score

# 205 :: 5/22/08
Question 205 has been Answered
Find the number z that has cumulative proportion 0.8. . .

Z-Score

# 206 :: 5/24/08
Question 206 has been Answered
The variable Z has a standard Normal distribution. a) Find the number z that has cumulative proportion 0.85. b) Find the number z such that the eve. . .

Z-Score

# 207 :: 5/24/08
Question 207 has been Answered
Suppose that the scores of architects on a particular creativity test are normally distributed.What percentage of architects have Z scores. (a) abov. . .

Z-Score

# 208 :: 5/27/08
Question 208 has been Answered
I am comparing 2 proportions of patients (before and after the introduction of a new quality-of-care project). The project is expected to reduce the p. . .

1-Sided Test, Hypothesis Test

# 209 :: 5/29/08
Question 209 has been Answered
In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security relatd jobs and found that. . .

Central Limit Theorem, binomial, Normal Approximation, Confidence Intervals

# 210 :: 5/29/08
Question 210 has been Answered
My local coffee house sells Colombian coffee beans to supermarkets in bags labelled 100g each. The tolerance of the automatic filling machine, lead. . .

Z-Score

# 211 :: 5/29/08
Question 211 has been Answered
State the main points of the Central Limit Theorem for a mean. B. Why is population shape of concern when estimating a mean? What does sample size hav. . .

Central Limit Theorem, Sample Size

# 212 :: 6/1/08
Question 212 has been Answered
How would I figure out a 90% and 95% confidence interval for the below informaion? What would be the formula? Can I figure this out in Excel or Mega. . .

t-distribution, Confidence Intervals, TINV, Margin of Error

# 213 :: 6/1/08
Let X be a random variable with the following probability distribution. Find the expectation and variance E(X) Var (X)of X. Value x of X P(X=x). . .

# 214 :: 6/2/08
Question 214 has been Answered
I am charged with sampling expense report submissions for accuracy. We get 8000 T&E claims, and want to sample a subset making inferences about the p. . .

1-sample t-test, Confidence Intervals, Sample Size

# 215 :: 6/3/08
Question 215 has been Answered
Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $45,000. Assum. . .

Standard Normal Curve, Confidence Intervals, Standard Deviation, Normally Distributed

# 217 :: 6/5/08
Volunteers at a teenage distress center have been assigned based on their skills and expertise. It's assumed that 40% are drug related, 25% sex relate. . .

# 218 :: 6/5/08
Question 218 has been Answered
what are the key terms in a verbal hypothesis that signify whether you are conducting a one-tailed or two-test? Give an example and explain your answe. . .

Hypothesis Test, One-Tailed Area

# 219 :: 6/6/08
Question 219 has been Answered
A z score of 1.04 shows a percentage value of?. . .

Z-Score

# 222 :: 6/7/08
Question 222 has been Answered
Fitness club surveys randomly selected members and found that the average weight of those questioned is 157 lb. Is this a parameter or a statistic?. . .

Parameter, statistic

# 224 :: 6/8/08
Question 224 has been Answered
I have some datas of arsenic concentration blockwise. can it be possible to compare the datas graphically, for blockwise distribution of the arsenic. . .

Interaction Plot

# 225 :: 6/9/08
Question 225 has been Answered
How do we calculate the upper and lower limits of one sided and two sided 95% confidence level of difference in proportion when comparing two groups i. . .

# 227 :: 6/10/08
how actually p value represents a distribution pattern whether it is normal or not? u explain the anderson-darling test regarding the normal graph. . .

# 229 :: 6/11/08
Question 229 has been Answered
Hi, what is the formula for converting z-scores to percentiles? I want to build a tool in Excel so i can get percentiles from test scores on normally . . .

NORMSDIST

# 230 :: 6/11/08
Question 230 has been Answered
a score that is 8 points above the mean corresponds to a z-score=0.05 What is the population standard deviation?. . .

Standard Deviation, Z-Score

# 231 :: 6/12/08
Question 231 has been Answered
A person gets 14/20 on a test in which each question has 5 answer choices. What is his 95% CI for his score?. . .

# 232 :: 6/12/08
Question 232 has been Answered
If a distribution of test scores is normal with a mean of 78 and a standard deviation of 11, what percent of the area lies below 60. . .

Z-Score

# 233 :: 6/13/08
Question 233 has been Answered
Between what two values of Z will 88% of the middle data values fall between?. . .

Z-Score

# 234 :: 6/13/08
Question 234 has been Answered
The third quartile of the age at marriage for females in US last year was 29.5 years. What percentage of women who married in the US last year were ol. . .

Quartile

# 237 :: 6/14/08
A sample of 100 one-dollar bills from the Subway cash register revealed that 16 had something written on them besides the normal printing (e.g., Bob . . .

# 238 :: 6/15/08
A random sample of rivets from 2 suppliers were compared to see what the mean diameter was from each and a test to determine whether the population me. . .

# 239 :: 6/16/08
Question 239 has been Answered
I have a data set where n=20. My problem is to find the score at exactly the 75th percentile assuming normality. I know the formula for z-score, the. . .

Z-Score

# 240 :: 6/17/08
Estimate probability P(6) for a binomial experiment within = 18, p = 0.30 by using the normal distribution. . .

# 241 :: 6/19/08
a university's administrator proposes to do an analysis of the proportion of graduates who have not fuond employment in their major field one year aft. . .

# 242 :: 6/19/08
When would you use regression correlation at your place of employment, in your education, or in politics. . .

# 243 :: 6/22/08
Examine the data below showing the weights (in pounds) of randomly selected checked bags for an airline's flights on the same day. (a) At α = .05. . .

# 244 :: 6/22/08
Mean output of solar cells of three types are measured six times under random light intensity over a period of 5 minutes, yielding the results shown. . . .

# 245 :: 6/22/08
Use the traditional method to test the given hypothesis. Assume that the samples are independent and that they have been randomly selected A resea. . .

# 247 :: 6/24/08
Question 247 has been Answered
Jeff: Can you possibly share the actual formula you are using in this application to produce the Adjusted Wald calculations? Thanks. . .

Adjusted Wald, Z-Score, Confidence Intervals

# 248 :: 6/24/08
the class ends the year with a mean of 68 and a stadard deviation of 9, the prof decides to bell curve the marks so that the top 10% gets an A (80%). . . .

# 249 :: 6/24/08
Question 249 has been Answered
A nationally standardized test is scaled so that the normally distributed scores have a mean of 80 and a standard deviation of 10 in the population. I. . .

Z-Score

# 250 :: 6/24/08
1)For n = 49, find the 90% confidence interval for x bar = 85 and = 2. Do not round! 2)A purchasing agent for a national chain of seafood restaur. . .

# 251 :: 6/25/08
How can I calculate the z-score for 2 test data that come from 2 tester, eg: 378 and 362?. . .

# 252 :: 6/26/08
Examine the data below showing the weights (in pounds) of randomly selected checked bags for an airline's flights on the same day. (a) At α = .05. . .

# 253 :: 6/26/08
Question 253 has been Answered
What are the 2 advantages of using Z power? If the z score is less than 0, what can be said of the corresponding raw score? If the z score is great. . .

Z-Score

# 254 :: 6/28/08
Body Temparatures. Human body Temp have a mean of 98.20F and standard deviation of 0.62F. Convert the given temparatures to z scores. A. 97.5F B. 9. . .

# 256 :: 6/30/08
19. A doctor reports that he/she has been experiencing a 15% rate of no-shows on appointments. Among 150 appointments, find the probability that ther. . .

# 257 :: 6/30/08
Question 257 has been Answered
A company is filling bags of rock salt to a level of 50 pounds. It believes that all bags are filled correctly, but would like to use a hypothesis tes. . .

Null Hypothesis , Alternative Hypothesis

# 259 :: 7/1/08
Question 259 has been Answered
What is the formula used to get percentile from z-score? I have z-scores but am using excel and want to be able to type in a formula to figure percen. . .

NORMSDIST

# 260 :: 7/1/08
Question 260 has been Answered
Suppose that the scores of architects on a particular creativity test are normally distributed. What percentage of architects have Z scores (a) above . . .

Z-Score

# 261 :: 7/1/08
Question 261 has been Answered
If your hypothesis is not correct, can the data collected still be used within a subsequent analysis.. . .

Hypothesis Test, p-value

# 262 :: 7/3/08
Question 262 has been Answered
with a mean of 150 and a standard deviation of 15 what is the probability of a student having a weight of less than 178 lbs.. . .

Z-Score

# 263 :: 7/6/08
Question 263 has been Answered
Determine the critical value Za/2 that corresponds to 94% level of confidence Compute the 90% confidence interval about m if the sample size, n, is. . .

Critical Value, Confidence Intervals, Margin of Error

# 265 :: 7/6/08
Question 265 has been Answered
An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above . . .

1-sample t-test

# 266 :: 7/8/08
Question 266 has been Answered
what is the difference between percentage and percentile?specially in cat like exams.. . .

Percentile

# 267 :: 7/8/08
how can i compute for the standard scores when i don't know what the SD is?. . .

# 268 :: 7/9/08
How would you demonstrate the Central Limit Theorem to classmates. . .

# 269 :: 7/9/08
Question 269 has been Answered
A classical experiment in extrasensory perception (ESP) consists of asking a subject to tell, without looking, the suit of each card in a deck of Zene. . .

Z-Score, Binomial Probability, Normal Approximation, binomial, BINOMDIST

# 271 :: 7/9/08
Question 271 has been Answered
Which type of data set can the mean not be calculated?. . .

skew, mean, Geometric Mean, Median

# 272 :: 7/10/08
Question 272 has been Answered
What is z-score? what information is provided by a z-score?. . .

# 273 :: 7/10/08
Discuss the characteristics of probability within the context of rolling a die.. . .

# 275 :: 7/11/08
Question 275 has been Answered
The lowest 25% of the normal distribution falls below what z-score and t-score. . .

T score, Z-Score

# 276 :: 7/11/08
Question 276 has been Answered
Why is population shape of concern when estimating a mean? What does sample size have to do with it?. . .

Normally Distributed

# 277 :: 7/14/08
Question 277 has been Answered
If an A is given to a student who scores 90% or above, what would the minimum z-score be for a 300 multiple choice question test with a mean of 195 an. . .

Z-Score

# 278 :: 7/15/08
Question 278 has been Answered
out of a random sample 167 students pass an exam out of the 300. how do you calculate an exact 99% confidence interval for the proportion of sudents w. . .

exact interval, Confidence Intervals

# 280 :: 7/16/08
Question 280 has been Answered
In normal distribution with mean 55 and atandard deviation 10,the area to the right of 55 is a) 0.6 b) 0.8 c) 0.9 d) 0.75. . .

# 281 :: 7/16/08
Question 281 has been Answered
in a normal distribution curve with mean as 55 and standard deviation as 10 what will be the area on the right side of the curve and how?. . .

# 282 :: 7/16/08
Question 282 has been Answered
In normal distribution with mean 55 and atandard deviation 10,the area to the right of 55 is a) 0.6 b) 0.8 c) 0.9 d) 0.75. . .

# 283 :: 7/19/08
Question 283 has been Answered
The lengths of pregnancies are normally distributed with a mean of 264 days and a standard deviation of 25 days. If 100 women are randomly selected, f. . .

Z-Score, Area between

# 285 :: 7/20/08
Question 285 has been Answered
A company is filling bags of rock salt to a level of 50 pounds. It believes that all bags are filled correctly, but would like to use a hypothesis tes. . .

# 287 :: 7/23/08
Question 287 has been Answered
in a study of 11000 car crashes it was found that 5720 of them occurred within 5 miles of home. use a 0.01 significance level to test tha claim that m. . .

Binomial Probability, binomial, BINOMDIST

# 288 :: 7/24/08
Question 288 has been Answered
Twenty-seven users completed a task, and each user did so with a combination of two variables, S and V, which can each have a value of "yes" or "no". . . .

Newton-Raphson, Logistic Regression, Maximum Likelihood

# 289 :: 7/25/08
Question 289 has been Answered
A standard I.Q. test produces normally distributed results with a mean of 100 and a standard deviation of 15. If an average I.Q. is defined to be any . . .

Z-Score, IQ Score

# 291 :: 7/26/08
Question 291 has been Answered
According to the standard normal curve, _____% of values should fall; within +/ 1 standard deviation(s) from the mean; +/- 3 standard deviation. . .

Standard Normal Curve, above .10

# 293 :: 7/28/08
Question 293 has been Answered
How can you use a Z score to interpret data in a school. . .

Z-Score

# 294 :: 7/28/08
Question 294 has been Answered
A test is normally distributed with a mean of 40 and a standard deviation of 7. (a) What score would be needed to be in the 85th percentile?. . .

Z-Score, Percentile, Percentile Rank

# 295 :: 7/28/08
Question 295 has been Answered
How can I calculate a Z score with only the mean and the standard deviation?. . .

Z-Score

# 296 :: 7/28/08
Question 296 has been Answered
What is the Z value that corresponds to a probability of .05?. . .

# 297 :: 7/28/08
Question 297 has been Answered
What is the formula for finding the t-statistic. . .

Newton-Raphson, t-statistic

# 298 :: 7/29/08
Question 298 has been Answered
a sample of 50 men with a mean of 35 and sd of 3.2 and alpha of .05, what is the z score, the critical value, the test value. . .

# 299 :: 7/30/08
Question 299 has been Answered
random variable x is normally distributed with mean of 250 and standard deviation of 50 find z-score for x=175. . .

Z-Score

# 301 :: 7/31/08
Question 301 has been Answered
What is the advantage of a t-score over a z-score?. . .

t-statistic, t-score

# 303 :: 8/1/08
Question 303 has been Answered
This question was put to me the other day; Whats the Z-score of 100? my reply no enough info without the standard deviation or the mean I cannot calcu. . .

# 304 :: 8/1/08
Question 304 has been Answered
Is a number whose z score is equal to zero equal to the mean?. . .

# 305 :: 8/2/08
Question 305 has been Answered
How do I determine what test statistic to use if given a sample of test scores for a present year and a previous year using a .05 significance level t. . .

Continuous Data, Discrete Data, Null Hypothesis

# 309 :: 8/4/08
Question 309 has been Answered
A cereal company claims that the mean weight of the cereal in its packets is 14 ounces. The weights in ounces of the cereal in a random sample of 8 of. . .

1-sample t-test, TDIST, t-score, t-statistic

# 310 :: 8/4/08
Various temperature measurements are recorded at different times for a particular day. the mean of 20 degrees C is obtained for 40 temperatures on 40 . . .

# 311 :: 8/4/08
Question 311 has been Answered
A random sample of 100 pumpkins is obtained and the mean circumference is found to be 40.5 cm. Assuming that the population standard deviation is know. . .

p-value, Null Hypothesis , Alternative Hypothesis , Z-Statistic, t-statistic

# 313 :: 8/5/08
Question 313 has been Answered
3 methods, A, B, and C are available for teaching a certain industrial skill. Only one of these methods is used in teaching a particular worker. The f. . .

Bayes Theorem , Conditional Probability, Addition Rule

# 314 :: 8/5/08
Question 314 has been Answered
I am doing A/B testing on an ecommerce web site. I have been working on rule of thumb of 500 vistors through each page or 50 conversions on one of the. . .

2-proportion test, A/B Testing

# 315 :: 8/5/08
Question 315 has been Answered
An engineer in an automotive factory wishes to know what the tire pressure is on all cars leaving the factory. She measures the tire pressure on a sa. . .

Standard Error of the Mean, Standard Deviation, Confidence Intervals, Critical Value, t-statistic

# 316 :: 8/5/08
Question 316 has been Answered
Hello, I work in Aerospace Engineering. Aerospace components are often subjected to cyclic loads and can fail in "fatigue". The designers design the p. . .

Sigma Level

# 317 :: 8/5/08
Question 317 has been Answered
Can the bell curve probability value be over the value of 1?. . .

Normal Curve, Bell Curve

# 318 :: 8/6/08
Question 318 has been Answered
A traffic study at one point on an interstate highway shows that vehicle speeds are normally distributed with a mean of 61.3 mph and a standard deviat. . .

Area between, Z-Score

# 319 :: 8/6/08
Question 319 has been Answered
A machine cuts circular filters from large rolls of material. If 7.3% of the filters fail to meet specifications, use the normal approximation to the . . .

binomial, Binomial Probability, Normal Approximation, Continuity Correction

# 320 :: 8/6/08
Question 320 has been Answered
Individual scores of a placement examination are normally distributed with a mean of 84.2 and a standard deviation of 12.8. If the score of an indi. . .

t-score, TDIST

# 321 :: 8/7/08
Question 321 has been Answered
A normal distributed population has a mean of 250 pounds and a standard deviation of 10 pounds. Given n = 20, what is the probability that this sample. . .

Area between

# 322 :: 8/7/08
Question 322 has been Answered
What effect does an increase in the level of confidence have on the width of the confidence interval?. . .

Confidence Level

# 325 :: 8/7/08
Question 325 has been Answered
A doctor knows from experience that 20% of the patients to whom he gives a high blood pressure drug will have undesirable side effects. Assume the doc. . .

BINOMDIST, Excel, Binomial Probability

# 326 :: 8/7/08
Question 326 has been Answered
What statistic would be applied if the independant variable is nominal and one dependant variable is nominal and one dependant variable is scale? Is t. . .

t-test

# 327 :: 8/8/08
Question 327 has been Answered
Want a sample size of about 60 (30 controls and 30 cases). At 5% significance and 80% power.How do i determine the standard deviation and mean differe. . .

Power, Standard Deviation, Mean Difference

# 329 :: 8/8/08
Question 329 has been Answered
A husband and wife make their decisions independently of each other, and then they compare their decisions. If they agree, the decision is made; if th. . .

Multiplication Rule

# 330 :: 8/9/08
Question 330 has been Answered
If you had a sample size of 50 and did not know the standard deviation of the population, would you use a t or a z statistics in your analysis? Why?. . .

t-test, z-test

# 331 :: 8/10/08
Question 331 has been Answered
When we reject the null hypothesis, we are certain that the null hypothesis is false ?. . .

Null Hypothesis

# 332 :: 8/10/08
Question 332 has been Answered
If our decision in a hypothesis test is to fail to reject the null hypothesis, then do we know that the null hypothesis must be true?. . .

Null Hypothesis

# 333 :: 8/10/08
Question 333 has been Answered
A woman sells an average of 300 books per month, with a standard deviation of 50. Over the next ten years, how many months will she sell more than 375. . .

Z-Score

# 334 :: 8/10/08
Question 334 has been Answered
find the z value so that 20% of the standard normal curve lies to the right of Z. . .

Z-Score

# 335 :: 8/10/08
Question 335 has been Answered
The random variable x has the following probability distribution. x 1 2 3 4 5 P(x) 0.5 0.2 0.1 0.1 0.1 Find the mea. . .

Expected Value, Random Variable, Standard Deviation

# 336 :: 8/11/08
Question 336 has been Answered
Why is population shape of concern when estimating a mean? What does sample size have to do with it?. . .

Central Limit Theorem

# 337 :: 8/11/08
Question 337 has been Answered
is the chi-square distribution used for inferences about the population mean when the standard deviation is unknown?. . .

Chi-Square

# 338 :: 8/11/08
Question 338 has been Answered
Is the chi-square distribution is a skewed distribution whose mean value is n for degrees of freedom larger than two?. . .

Chi-Square

# 339 :: 8/12/08
Question 339 has been Answered
My question is really about sample size. Say you work at a facility and want to perform an assessment of your safety culture this would involve mul. . .

Sample Size, Margin of Error

# 340 :: 8/12/08
Question 340 has been Answered
Hi Jeff, You have lots of great info on your site; thanks! However, I'm trying to reconcile some different items and they seem to disagree. Can you. . .

# 342 :: 8/13/08
Question 342 has been Answered
In a one-way ANOVA, there are three treatments with n1 = 5, n2 = 6 and n3 = 5. The rejection region for this test at the 5% level of significance is__. . .

ANOVA, F-statistic

# 343 :: 8/13/08
Question 343 has been Answered
The following data show samples of three chain stores in three different locations in one town and the amount of dollars spent per customer per visit.. . .

ANOVA

# 344 :: 8/14/08
Question 344 has been Answered
Explain the difference between testing a single mean and testing the difference between two means. What two assumptions must be met when one is using . . .

Standard Deviation, z-test, Normally Distributed, Homogeneity of Variance

# 345 :: 8/14/08
Question 345 has been Answered
What are the 5 steps involved in hypothesis testing using the traditional/classical method; Can you use a simple real world example to explain it to m. . .

Null Hypothesis , Alternative Hypothesis , Hypothesis Test, Steps in Hypothesis Test

# 346 :: 8/14/08
Question 346 has been Answered
Why is population shape of concern when estimating a mean?. . .

# 347 :: 8/14/08
Question 347 has been Answered
Why is population shape of concern when estimating a mean? What does sample size have to do with it?. . .

# 348 :: 8/15/08
Question 348 has been Answered
A random variable X is normal distributed with a mean of 250 and standard deviation of 50. Given that X = 175, what is its corresponding z-score? Rou. . .

Z-Score

# 349 :: 8/15/08
Question 349 has been Answered
A bank has determined that the monthly balances of savings accounts of its customers are normaly distributed with an average balance of $1200 and stan. . .

Z-Score

# 350 :: 8/16/08
Question 350 has been Answered
A robot, when working properly, produces 5% or less defective items. whenever the robot produces more than 5% defective items, i needs repair. A rando. . .

Continuity Correction, Normal Approximation, binomial, 1-Sample Proportion Test

# 351 :: 8/17/08
Question 351 has been Answered
As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, the unpopped ke. . .

Confidence Intervals

# 353 :: 8/19/08
Question 353 has been Answered
A surgical technique is performed on eight patients. You are told that there is an 80% chance of success. a) Construct a binomial distribution. . . .

BINOMDIST, Binomial Probability

# 354 :: 8/20/08
Question 354 has been Answered
A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were 3.0. . .

t-statistic

# 355 :: 8/20/08
Question 355 has been Answered
If Range = (6 * Standard Deviation), can it be concluded that Data is normal. . .

Nomal Distribution, Probability Plot

# 356 :: 8/24/08
Question 356 has been Answered
The mean weight of 500 students is 151 lbs and the standard deviation is 15 lbs. Assuming the weights are normally distributed, find out how many stu. . .

Area between, Z-Score

# 357 :: 8/25/08
Question 357 has been Answered
Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them. . .

Confidence Intervals, Normal Approximation to Binomial , Proportion

# 358 :: 8/25/08
Question 358 has been Answered
In the same set of data,can two or more elements have the same z score.. . .

Z-Score

# 359 :: 8/27/08
Question 359 has been Answered
You have a normal distribution and your subject has a z score = 0. What percentage of the group will be below your subject?. . .

# 360 :: 8/27/08
Question 360 has been Answered
What does a negative z-score represent? eg. -0.381. . .

# 361 :: 8/30/08
Question 361 has been Answered
If I have a formula that predicts the winners of football games and it picked 600 out of 20000 games with 70% of the 600 being winners how can I estim. . .

# 362 :: 9/1/08
Question 362 has been Answered
Popcorn kernels take between 100 and 200 seconds to pop. What sample size (number of kernels) would be needed to estimate the true mean seconds to pop. . .

Small Sample, Sample Size, Margin of Error, Confidence Intervals

# 364 :: 9/4/08
Question 364 has been Answered
A sample of 20 pages was taken without replacement from the 1,591-page phone directory Ameritech Pages Plus Yellow Pages. On each page, the mean area . . .

Margin of Error, Confidence Intervals, Sample Size

# 366 :: 9/4/08
Answer in Progress
If I have 3 tables in the classroom with 16 girls and 8 boys in the class, what are the chances of 8 girls sitting at one table when seats are assigne. . .

# 367 :: 9/5/08
Question 367 has been Answered
find the area under standard normal curve which lies (a) to the right of Z=1.76,(b)to the left of Z=.94,(c)to the right of Z=-.65,(d)b/w Z=.34 & Z=.62. . .

Area between, Z-Score

# 368 :: 9/5/08
Question 368 has been Answered
in a random sample of 200 person of a town 120 are found to the tea drinker.In a random sample of 500 person of another town 240 are found to be tea d. . .

Normal Approximation, 2-proportion test, Binomial Probability

# 369 :: 9/5/08
Question 369 has been Answered
A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on very accurate scale. The results in grams were 3.087 3.. . .

Margin of Error, Sample Size, Confidence Intervals

# 370 :: 9/6/08
Question 370 has been Answered
The accounting department at Weston reports that it takes two construction workers a mean of 32 hours and a standard deviation of 2 hours... Determin. . .

Area between, Z-Score

# 371 :: 9/8/08
Question 371 has been Answered
Can you give me a formula to calculate sample size?. . .

Sample Size, Margin of Error

# 372 :: 9/8/08
Question 372 has been Answered
Can you please direct me to a site that would have an illustration of the normal curve that also includes cumulative percentiles, Z-score equivalents,. . .

SAT Scores, Normal Curve

# 374 :: 9/9/08
Question 374 has been Answered
A sample of size n = 14 is selected from a normal population to construct a 95% confidence interval estimate for a population mean. The interval was c. . .

# 375 :: 9/9/08
why are histograms more appropate than bar graphs. . .

# 376 :: 9/10/08
Question 376 has been Answered
What statistical tests can I perform to compare two groups asked the same question, when the question has a yes/no answer and the sample groups are di. . .

2-proportion test

# 377 :: 9/10/08
Question 377 has been Answered
A sample of households that subscribe to the United Bell Phone Company revealed the following numbers of calls received by each household last week. D. . .

mean, Median, Standard Deviation

# 378 :: 9/10/08
Question 378 has been Answered
We have administered an anxiety test to all members of the class. The mean anxiety score is 71 and the standard deviation is 9. (higher score=higher a. . .

Z-Score

# 379 :: 9/11/08
Question 379 has been Answered
1 a. with a mean of 300 and a standard deviation of 80, how high a score do you need to be in the top 30%? 1 b. What is the interquartile range for. . .

Interquartile Range, Z-Score

# 380 :: 9/11/08
Question 380 has been Answered
What is the relationship between the sign of the correlation coefficient and the sign of the slope of the regression line?. . .

Correlation, Regression Line

# 381 :: 9/13/08
Question 381 has been Answered
If I know the T-score for those who made an A on a test is 60, the z-score for those that made a B is .5, the number of students total is 200, how can. . .

Z-Score

# 383 :: 9/15/08
Question 383 has been Answered
Briefly describe the concept of a confidence interval and provide an example.. . .

Confidence Intervals

# 384 :: 9/16/08
Test at the 5% level of significance whether the true mean time it takes for luggage to reach the travelers is less than 17 minutes. Determine the nul. . .

# 385 :: 9/16/08
Question 385 has been Answered
Given that the traveling distance for a population of college students is normally distributed with the mean of 10 kilometers and standard deviation e. . .

Z-Score

# 386 :: 9/17/08
Question 386 has been Answered
I am calculating the effectiveness of an educational intervention using a pretest-posttest design. I plan to run an ANCOVA on the scores with the pret. . .

Covariate, ANCOVA, ANOVA

# 388 :: 9/17/08
Question 388 has been Answered
In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made. . .

2-proportion test, Binomial Probability, Normal Approximation

# 389 :: 9/18/08
Question 389 has been Answered
How do you dertermine a z-score for continuous data?. . .

Z-Score

# 390 :: 9/18/08
Question 390 has been Answered
How do you find the normal distribution when the mean is 50 witha standard deviation between scores of 32 and 47?. . .

Area between, Z-Score

# 391 :: 9/18/08
Question 391 has been Answered
An engineer in an automotive factory wishes to know what the tire pressure is on all cars leaving the factory. She measures the tire pressure on a sa. . .

Standard Error of the Mean, t-statistic, Confidence Intervals, Critical Value

# 395 :: 9/19/08
Question 395 has been Answered
What is the Variance, Standard Deviation and Range of the following set of scores? 20,24,26,22,18,16,18 and then 10,15,12,18,19,16,12. . .

# 396 :: 9/19/08
what is the bottom of 20% of SAT. . .

# 397 :: 9/19/08
Question 397 has been Answered
mean score 100,standard deviation 20, z score-5 , what is the raw score?. . .

Z-Score, Raw Score from Z-score

# 398 :: 9/19/08
What is the formula for the exclusive range? What is the formula for the inclusive range?. . .

# 399 :: 9/20/08
Question 399 has been Answered
When you calculate CIs for time on task, I notice that you use the critical value from the t-distribution (TINV(0.05, degrees_of_freedom)). But when y. . .

exact interval, Binomial Probability, TINV, Adjusted Wald, Wald Interval, Normal Approximation, Small Sample

# 400 :: 9/20/08
Question 400 has been Answered
What is the standard general score conversion formula? Is this the same as a z-score formula? Which leads me to ask How do you convert from one standa. . .

Standard Score

# 401 :: 9/20/08
Question 401 has been Answered
A woman wrote to DearAbby and claimed that she gave birth 308 days after a visit from her husband, who is in the Navy. Lengths of pregnancies have a . . .

Z-Score, Unusual Event

# 402 :: 9/21/08
Question 402 has been Answered
How can I compute a one-sided 97.5% confidence interval using SPSS for this ? IN a cohort of 121 eyes treated with drug A, 3 eyes experience a drug . . .

SPSS, Confidence Intervals, 1-sided Interval

# 403 :: 9/22/08
Question 403 has been Answered
Based on information obtained from a sample of 54, a 98% confidence interval for the average profit level of regional banks is given by 67.4 million t. . .

Standard Deviation, Margin of Error, Critical Value, Confidence Intervals, Confidence Level

# 404 :: 9/22/08
Question 404 has been Answered
How do you calculate a standard deviation when your data is so large you can not enter it into the calculator. (I have 50 pcs of data). . .

# 405 :: 9/22/08
Question 405 has been Answered
Marge and Joe have five daughters. They decide to have another baby because they are sure the next one will be a boy (after all, what are the odds of . . .

BINOMDIST, Multiplication Rule, Gambler's Fallacy, Probability Mass Function

# 408 :: 9/23/08
Question 408 has been Answered
Use Excel, or MINITAB to fit the regression model, including residuals and standardized residuals: DATA SET E Ages and Weights of 31 Randomly Chose. . .

Minitab, Regression Analysis, Residuals

# 409 :: 9/24/08
Question 409 has been Answered
What is the height of a man with the z score of -1.7?. . .

Z-Score

# 410 :: 9/24/08
Question 410 has been Answered
You take a random sample of pizzas sold during a one hour period over the next week. Group 1 and Group 2 The results are shown in the table to the a. . .

2-sample t-test

# 411 :: 9/24/08
Question 411 has been Answered
Do you have any hints how I can figure out critical values at the significance level? Can you figure this out in excel or megastat? Is there a equat. . .

NORMSINV, TINV

# 412 :: 9/27/08
Question 412 has been Answered
If you have 30 espondents identifying their political preference(i.e.,Democrat, Republican, Independent),what would be the expected frequency for each. . .

# 413 :: 9/27/08
Question 413 has been Answered
In order to meet the sample assumption associated with parametrics statistics, how many subjects do you need? a)20 b)30 c)50 d)100. . .

# 414 :: 9/27/08
Question 414 has been Answered
If you have 100 respondents identifying their gender, what would be the expected frequency for each category? a)25 b)50 c)75)d)100. . .

# 415 :: 9/27/08
Question 415 has been Answered
how do i find the lower 25% and upper 75% and the interquartile range. . .

Interquartile Range

# 416 :: 9/27/08
Question 416 has been Answered
Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a second group do not. After 6 months, both groups . . .

2-sample t-test, Hypothesis Test

# 417 :: 9/27/08
Question 417 has been Answered
Could you detail the value of using standard scores (Z scores) to compare relative performance of individual test scores.. . .

Z-Score

# 418 :: 9/27/08
Question 418 has been Answered
Dear Stats Person, Here is my question. If a person were to guess a number from 1-10, the chance of guessing a 4 would be 0.1. If 5 people were a. . .

BINOMDIST, Binomial Probability, Binomial pmf

# 419 :: 9/28/08
Question 419 has been Answered
Suppose two events are independent. One event has probability of 0.25, while the other has probability of 0.59.. . .

Multiplication Rule

# 420 :: 9/28/08
Question 420 has been Answered
In one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kWh and a stan. . .

Z-Score

# 421 :: 9/28/08
Question 421 has been Answered
A surgical technique is performed on eight patients. You are told that there is an 80% chance of success. Construct a binomial distribution. Find. . .

# 422 :: 9/28/08
Question 422 has been Answered
A newspaper finds that the mean number of typographical errors per page is five. Find the probability that: 1. Exactly five typographical errors wi. . .

# 423 :: 9/28/08
Question 423 has been Answered
the lengths of human pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. What is the probability that a . . .

Z-Score

# 424 :: 9/29/08
Question 424 has been Answered
A recent article in a computer magazine suggested that the mean time to fully learn a new software program is 40 hours. A sample of 100 first-time use. . .

1-sample t-test, Alternative Hypothesis , Null Hypothesis , test statistic, p-value

# 425 :: 9/29/08
A real estate agent has 2 tours. The first tour through N1and has 10 homes for sale, whereas the second tour through N2and has 5 homes for sale. The r. . .

# 426 :: 9/29/08
Question 426 has been Answered
can individual scores of a 542 student be converted into percentage and fed into spss for anova and tukey test. . .

Percent Score, ANOVA

# 427 :: 9/29/08
Question 427 has been Answered
Set up a model to test whether there are differences in mean ... DATA SET E Ages and Weights of 31 Randomly Chosen U.S. Nickels (n = 31 nickels) Nicke. . .

# 428 :: 9/29/08
Question 428 has been Answered
Each student in an experiment was told to look at 100 cars and count the number of people wearing the seat belts. The mean score for the class was fou. . .

Z-Score

# 429 :: 9/29/08
Question 429 has been Answered
A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule. . .

Normal Approximation to Binomial , 1-Proportion Test

# 430 :: 9/29/08
Question 430 has been Answered
Individual scores of a placement examination are normally distributed with a mean of 84.2 and a standard deviation of 12.8. If the score of an indi. . .

# 432 :: 9/30/08
Question 432 has been Answered
Assume that the population of heights of male college students is approximately normally distributed with mean m of 68 inches and standard deviation s. . .

TDIST, t-score

# 433 :: 10/1/08
Question 433 has been Answered
My data set is non-normal (cycle time). Can I convert the data into "Good and Bad" based on a specification and then find a Z value to estimate my sig. . .

Cycle Time, Non-Normal Data, Log Transformation

# 435 :: 10/1/08
Question 435 has been Answered
Parametric and Nonparametric Data Identification Assignment Label each of the following situations P if it is an example of parametric data or NP. . .

Non-Parametric, Parametric

# 436 :: 10/1/08
Question 436 has been Answered
when is ecological correlation appropriate? When is it not useful?. . .

Ecological correlation

# 437 :: 10/1/08
how can i interpret standard or z scores?. . .

# 438 :: 10/2/08
How do i compute for the standard score (z-score)of the following data? How will the graph look like? 53 53 50 45 45 43 42 42 41 40 39 39 . . .

# 439 :: 10/2/08
I have a jar containing 100,000 marbles. There are 6 colors of marbles in the jar and they are present at frequencies of 2%, 2%, 4%, 10%, 57%, 25%. . . .

# 440 :: 10/2/08
How would you represent score of Y based on a known value of X? (a)Y (b)y-intercept (c)Y'(d)Y=Xa. . .

# 441 :: 10/2/08
Question 441 has been Answered
Which of the following Excel Function calulated the point at the regression line crosses the y-axis (a)SLOPE (b)CORREL (c)INTERCEPT (d)PEASON. . .

# 442 :: 10/2/08
Question 442 has been Answered
Using the regression Formula with slope=.704 and intercept=.719, what would the predicted college GPA be for a student whose current high school GPA=3. . .

# 443 :: 10/2/08
Question 443 has been Answered
A postive trend line is associated with what type of slope? (a)Negative slope (b)Direct slope (c)Postive slope (d)Nondirectional slope. . .

# 444 :: 10/2/08
Question 444 has been Answered
What mut be done to categorical variables in order to use them in a regression analysis? (a)Nothing (b)Dummy coding (c)Problem coding (d)Categorical c. . .

# 445 :: 10/2/08
Question 445 has been Answered
What must be used to examine an outcome that is predicted from two independent variables? (a)Multivariate regression (b)Multiple regression (c)Simple . . .

# 446 :: 10/2/08
Question 446 has been Answered
When using two predictor variables, these variables should be (a)Correlated (b)Related (c)Independent (d) Dependent. . .

# 447 :: 10/2/08
If he correlaion between X and Y is equal to -1.0, what do we know about the prediction of Y by X? (a)It's negative (b) It's postive (c)It's perfect (. . .

# 450 :: 10/3/08
Question 450 has been Answered
A researcher is interested in estimating the average salary of fire fighters in a large city. He wants to be 95% confident that his estimate is correc. . .

Margin of Error, Sample Size

# 451 :: 10/3/08
Question 451 has been Answered
A sample of the math test scores of 35 fourth-graders has a mean of 82 with a standard deviation of 15. Find the 95% confidence interval of the mean. . .

Confidence Intervals, Confidence Level

# 452 :: 10/3/08
Question 452 has been Answered
why does a z score always have a mean of 0 and a standard deviation of 1?. . .

Standard Normal Curve

# 453 :: 10/4/08
Question 453 has been Answered
A central university has a student population of 60,000. The university is interested in determining what proportion of them is in favour of a new gra. . .

Sample Size, Margin of Error

# 454 :: 10/4/08
what concerns arise from using formulae to calculate standard scores. . .

# 455 :: 10/4/08
Question 455 has been Answered
Assume scores are normally distributed with a mean of 10 and std dev of 2. Find the first quartile Q1, which is the score separating the bottom 25% fr. . .

Quartile

# 456 :: 10/4/08
Question 456 has been Answered
I am trying to find out if a difference between two response sets is significant. I asked 98 boys what modalities they thought were attractive to girl. . .

2-proportion test

# 457 :: 10/4/08
What is a simple but legitimate power analysis formula? I am trying to do qualitative research on African American HS boys in the Midwest. I am using . . .

# 458 :: 10/5/08
Question 458 has been Answered
In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found th. . .

Confidence Intervals, Normality Assumption

# 459 :: 10/5/08
Question 459 has been Answered
How do you calculate a participant score if she was at the 67th percentile? I only have the standard deviation of the population and the mean. s = 27 . . .

Percent Score, Percentile, Z-Score

# 460 :: 10/5/08
Question 460 has been Answered
20% kids danced. If 10 were selected at random, find probability that exactly four danced.. . .

BINOMDIST, Binomial pmf

# 461 :: 10/6/08
Question 461 has been Answered
My question is on Measurement system analysis (MSA). My metric is lead time. I calculated it from the system (computer database) which stores all th. . .

Gage R&R

# 462 :: 10/6/08
Question 462 has been Answered
Olympic Track related question: You know the last 5 race times at the same distance for 8 runners competing in a race. As such, you can calculate the. . .

Z-Score

# 463 :: 10/6/08
Question 463 has been Answered
Find the probability of correctly answering the first 2 questions on a multiple choice test if random guesses are made and each question has 3 possibl. . .

Multiplication Rule

# 464 :: 10/7/08
Question 464 has been Answered
How do you know when to use a t-score instead of a z-score and vice versa?. . .

Z-Score, t-score

# 465 :: 10/7/08
Question 465 has been Answered
A sample of 20 pages was taken without replacement from the 1,591-page phone directory Ameritech Pages Plus Yellow Pages On each page, the mean area d. . .

# 466 :: 10/7/08
Question 466 has been Answered
Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn counted 773 kernels and put them in a popp. . .

# 467 :: 10/7/08
Question 467 has been Answered
The Web-based company Oh Baby! Gifts has a goal of processing 95 percent of its orders on the same day they are received. If 485 out of the next 500 o. . .

1-Proportion Test, Normal Approximation

# 469 :: 10/8/08
Mean output of solar cells of three types are measured six times under random light intensity over a period of 5 minutes, yielding the results shown. . . .

# 470 :: 10/9/08
Question 470 has been Answered
A telescope manufacturer wants its telescopes to have standard deviations in resolution to be significantly below 2 when focusing on objects 500 light. . .

Chi-Square Distribution, Confidence Intervals, Standard Deviation, Variance

# 471 :: 10/9/08
Question 471 has been Answered
A central university has a student population of 60,000. The university is interested in determining what proportion of them is in favour of a new gra. . .

Margin of Error, Confidence Intervals, Sample Size

# 474 :: 10/12/08
Question 474 has been Answered
The central university has a student population of 60000. The university is interested in determining what proportion of them is in favour of a new gr. . .

# 475 :: 10/12/08
Question 475 has been Answered
A telephone manufacturer wants its telescope to have standard deviation in resolution to be significantly below 2 when focusing on object 500 light-ye. . .

Standard Deviation, Chi-Square, Chi-Square Distribution

# 476 :: 10/13/08
Question 476 has been Answered
Does normal distribution is something to do with Altman Z-Score?. . .

Altman Z-Score, Z-Score

# 481 :: 10/20/08
Question 481 has been Answered
a centre university has a student population of 60000. the university is interested in determining what proportion of them is in favour of a new gradi. . .

# 482 :: 10/20/08
Question 482 has been Answered
a telescpoe manufacturur wants its telescopes to have standard deviations in resolution to be significantly below 2 when focusing on objects 500 light. . .

# 483 :: 10/21/08
Question 483 has been Answered
I have a research study where we have a "test" and a "control" group. We calculated a market share percentage for both groups, the test group was in . . .

McNemar Chi-Square , Chi-Square

# 484 :: 10/25/08
Question 484 has been Answered
With a normal distribution of 50 and standard deviation of population =10, how do I figure out the score at the 40th percentile? How do I figure out t. . .

Z-Score, Area between, Percent Score

# 485 :: 10/27/08
Question 485 has been Answered
Assume that the heights of 5 year old boys are normally distribued with a mean of 100cm and a standard deviation of 60. What is the sampling distribut. . .

TINV, Confidence Intervals, Standard Error of the Mean, Standard Deviation of the Mean

# 486 :: 10/28/08
Question 486 has been Answered
1.A telescope manufacturer wants its telescopes to have standard deviations in resolution to be significantly below 2 when focusing on objects 500 lig. . .

# 487 :: 10/28/08
Question 487 has been Answered
Find a confidence interval for the mean assuming that each sample is from a normal population. Mean = 127, s = 27, n = 16. Find the 90% Confidence Int. . .

TINV, t-distribution, Confidence Intervals

# 491 :: 10/30/08
Using continuity Correction. There are many situations in which a normal distribution can be used as a good approximation to a random variable that ha. . .

Continuity Correction

# 492 :: 11/3/08
Answer in Progress
if an eligible couple on an average has 3.3 children then the birth rate will be?. . .

# 493 :: 11/4/08
Question 493 has been Answered
On a police sergeants exam, the historical mean scored was 80 with a standard deviation of 20. Four offiers scored 195,175,191, and 189 respectively. . . .

Empirical Rule, Z-Score, Unusual Event, Percent Score

# 494 :: 11/4/08
Question 494 has been Answered
If the average price of a new home is 145,000 what is the minimum and maximum prices of the houses a contractor will need to build to include the midd. . .

Z-Score, Area between

# 495 :: 11/4/08
The EPA range for a car is 20-28mpg, how large of a sample would be required to estimate your mean mpg with an error of +/- 1 mpg with 90% confidence. . .

Sample Size

# 497 :: 11/6/08
Question 497 has been Answered
A random sample of n=64 children of working mothers showed that they were absent from school an average of 5.3 days per term, with a standard deviatio. . .

Confidence Intervals, Confidence Level

# 498 :: 11/7/08
Question 498 has been Answered
During the next hour, five customer arrivals are expected. What is the probability that more than five customers will show up (according to the Poisso. . .

Poisson, Poisson Distribution

# 499 :: 11/7/08
Question 499 has been Answered
A newspaper finds that the mean number of typographical errors per page is five. Find the probability that: a. Exactly five typographical errors will. . .

Poisson, Poisson Distribution

# 500 :: 11/7/08
Question 500 has been Answered
In a recent year grade 8 Washington State public school students taking a mathematics assessment test had a mean score of 276.1 with a standard deviat. . .

Percent Score, Area between, Z-Score

# 501 :: 11/7/08
Question 501 has been Answered
In a survey of adults, 68% thought that DNA test for identifying an individual were very reliable. You randomly select 24 adults and ask each if he or. . .

BINOMDIST, Binomial Probability, Continuity Correction, Normal Approximation, Normal Approximation to Binomial

# 502 :: 11/7/08
Question 502 has been Answered
Administrative staff based at a business school in the UK are advised to take a 15 minute break from their personal computer after working on it for 9. . .

Confidence Intervals, TDIST, t-test, Z-Score

# 503 :: 11/7/08
Question 503 has been Answered
Choose a variable and collect data for at least three different groups (samples). Compare the means of the three groups using the one-way ANOVA techni. . .

ANOVA, F-statistic

# 504 :: 11/9/08
Question 504 has been Answered
Calculate the 95% confidence interval on the following GPA's from 30 randomly selected students. 0.979 0.891 0.962 0.858 0.909 0.936 0.963 0.9. . .

Confidence Intervals, Margin of Error, t-statistic

# 505 :: 11/11/08
Question 505 has been Answered
Calculate a 98% confidence interval for the following data 15.7,15.7,15.5,15.2,15.2,15.1,15.3.. . .

Confidence Intervals, TINV, Margin of Error, t-statistic

# 506 :: 11/12/08
Question 506 has been Answered
Suppose you are planning a sample of employees to determine the monthly average # of vacation days. Standards set: Confidence level of 99% and an erro. . .

Sample Size, Margin of Error, Confidence Intervals

# 507 :: 11/12/08
Question 507 has been Answered
In a survey of 500, 60% responded positively to an value question. Calculate a confidence level at 95% to get an interval estimate for proportion?. . .

Sample Size, Confidence Intervals, Proportion

# 508 :: 11/13/08
Question 508 has been Answered
In a national wide survey a researcher expects 30 percent of the population will agree with an value statement. He wishes to have less than 2% error a. . .

Sample Size, Margin of Error, Confidence Level

# 509 :: 11/13/08
Question 509 has been Answered
A researcher expects the population proportion of the Cubs Fans in Chicago to be 80%. Error of less than 5% confident of an estimate to be made from a. . .

Confidence Intervals, Sample Size, Margin of Error

# 510 :: 11/13/08
Question 510 has been Answered
Survey to determine what proportion of new car buyers continue to have their car serviced at the dealership after warranty ends. Estimates 30% of cust. . .

Sample Size, Confidence Level

# 511 :: 11/13/08
Question 511 has been Answered
A machine produces 3 inch nails. A sample of 100 nails is selected, and it is found that 25 are shorter than 3 inches. Find the 95% confidence interv. . .

Proportion, Confidence Intervals, One-Tailed Area

# 512 :: 11/14/08
Question 512 has been Answered
When estimating the mean of a population, how large must the sample be in order that the 95% error margin is 1/8 the standard deviation?. . .

Sample Size, Margin of Error, Standard Deviation, Standard Error of the Mean

# 513 :: 11/17/08
Question 513 has been Answered
I have a question about SEYhat in time-series regression for N=1 subject.... I want to know whether the StdError of the fitted score (SEYhat) can. . .

Time-Series, Regression Analysis, autocorrelation

# 514 :: 11/17/08
Question 514 has been Answered
I am trying to assess the impact of an event on a population. I ran a survey before the event and then I ran the survey after the event. The collect. . .

Paired t-test, Within Subjects, 1-Sided Test, One-Tailed Test

# 515 :: 11/19/08
Question 515 has been Answered
I run various A/B Split tests online. I always set all my tests for 10,000 visitors so page A and B are each equally rotated 5,000 times. My problem. . .

2-proportion test, Normal Approximation to Binomial , Power, A/B Testing

# 516 :: 11/19/08
Question 516 has been Answered
Given a mean score of 70, standard deviation of 15,percentile of 23.Find the Z score,T score and raw score. Please explain how to work backward on a . . .

T score, Percent Score, Z-Score

# 517 :: 11/22/08
Question 517 has been Answered
An executive drives his vehicle from home to work daily. Driving times are normally distributed with a mean of 35 minutes and standard deviation of 8. . .

Z-Score, Area between, above .10

# 519 :: 11/23/08
Question 519 has been Answered
Fill in the P (X=x) values in the table to give legitimate probability distribution for the discrete random variable X, whose possible values are -4, . . .

Random Variable, Probability, Compliment Rule

# 520 :: 11/23/08
Question 520 has been Answered
Your company asks you to compare a new advertising campaign and the old one. Sample data on the accounts as follows: Old: 40, 28, 35, 38, 31, 42, 26,. . .

Confidence Intervals, Median, Mode, mean, t-statistic, Standard Error of the Mean

# 521 :: 11/24/08
Question 521 has been Answered
The width of a confidence estimate for a proportion will be: a. Narrower for a 99% confidence interval than for a 95% confidence interval. b. Wider . . .

Confidence Level, Confidence Intervals, Proportion

# 523 :: 11/24/08
Question 523 has been Answered
Use the given degree of confidence and sample data to construct a confidence interval for the population mean x. Assume that the population has a norm. . .

Confidence Intervals, TINV

# 524 :: 11/24/08
Question 524 has been Answered
Discuss how t test can be employed in hypothesis testing by the use of directional vs. nondirectional hypotheses. Discuss types of research where usi. . .

t-score, Z-Score, directional test, nondirectional test, 1-Sided Test

# 525 :: 11/28/08
Question 525 has been Answered
Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study, researchers gave lovastatin to 2,325 people and an i. . .

2-proportion test, Normal Approximation to Binomial

# 526 :: 11/28/08
Question 526 has been Answered
To test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were hande. . .

2-sample t-test, Homogeneity of Variance, Equal Variances, F-test, Levine test

# 527 :: 11/28/08
Question 527 has been Answered
A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of $5.29 with a standard deviation of $3. . .

Homogeneity of Variance, F-test, Levine test

# 528 :: 11/28/08
Question 528 has been Answered
In a bumper test, three types of autos were deliberately crashed into a barrier at 5 mph, and the resulting damage (in dollars) was estimated. Five te. . .

ANOVA

# 530 :: 12/2/08
Question 530 has been Answered
What score would it have taken to be in the 90th percentile in a test with a mean of 40 and standard deviation of 7. . .

Z-Score, Percent Score

# 531 :: 12/4/08
What is higher a z score of .500 or a raw score of 17. . .

# 532 :: 12/5/08
Question 532 has been Answered
Based on the genotypes of parents, offspring are expected to have genotypes distributed in such a way that 25% have genotypes denoted by AA, 50% have. . .

Chi-Square, Goodnees of Fit

# 533 :: 12/6/08
I need help on understanding multiple logistic regression, especially inference, goodness-of-fit, and calculating Likelihood Ratio Chi-Square using G^. . .

# 534 :: 12/6/08
Question 534 has been Answered
Sixty-four students in an introductory college economics class were asked how many credits they had earned in college, and how certain they were about. . .

Chi-Square, CHIDIST

# 535 :: 12/6/08
Question 535 has been Answered
A student team examined parked cars in four different suburban shopping malls. One hundred vehicles were examined in each location. Research question:. . .

Chi-Square, CHIDIST

# 536 :: 12/6/08
Question 536 has been Answered
High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot coll. . .

Chi-Square, CHIDIST

# 537 :: 12/6/08
Question 537 has been Answered
Can people really identify their favorite brand of cola? Volunteers tasted Coca-Cola Classic, Pepsi, Diet Coke, and Diet Pepsi, with the results shown. . .

2-proportion test, Chi-Square

# 538 :: 12/9/08
Question 538 has been Answered
When would it be appropriate to use ANOVA and when is it appropriate to use a paired t test? Be specific and give examples.. . .

ANOVA, Paired t-test

# 539 :: 12/9/08
Question 539 has been Answered
The following sample observations were randomly selected X: 5 3 6 3 4 4 6 8 Y: 13 15 7 12 13 11 9 5 Determine the coefficient of correlati. . .

Correlation, coefficient of determination

# 540 :: 12/9/08
Question 540 has been Answered
A sample of 36 observations is selected from a normal population. The sample mean is 21, and the sample standard deviation is 5. Conduct the following. . .

1-sample t-test, 1-tailed test, Null Hypothesis , calculating mean, sample variance, Standard Deviation

# 541 :: 12/9/08
Question 541 has been Answered
A stockbroker at Critical Securities reported that the mean rate of return on a sample of 10 oil stocks was 12.6 percent with a standard deviation of . . .

F-test, Homogeneity of Variance, Unequal Variances, Levine test

# 542 :: 12/9/08
Question 542 has been Answered
A financial analyst wants to compare the turnover rates, I percent, for shares of oil-related stocks versus other stocks, such as GE and IBM. She sele. . .

2-sample t-test, Unequal Variances

# 544 :: 12/10/08
Question 544 has been Answered
(a) How does correlation analysis differ from regression analysis? (b) What does a correlation coefficient reveal? (c) State the quick rule for a sign. . .

Correlation, correlation coefficient , Regression Analysis, significant correlation

# 545 :: 12/10/08
Question 545 has been Answered
In the following regression, X = weekly pay, Y = income tax withheld, and n = 35 McDonalds employees. (a) Write the fitted regression equation. (b) S. . .

Regression Analysis, Slope

# 546 :: 12/10/08
Question 546 has been Answered
In the following regression, X = total assets ($ billions), Y = total revenue ($ billions), and n = 64 large banks. (a) Write the fitted regression eq. . .

Regression Analysis, Slope, Regression Equation

# 548 :: 12/10/08
Question 548 has been Answered
A researcher used stepwise regression to create regression models to predict BirthRate (births per 1,000) using five predictors: LifeExp (life expecta. . .

Stepwise Regression, Regression Analysis

# 549 :: 12/10/08
Question 549 has been Answered
An expert witness in a case of alleged racial discrimination in a state university school of nursing introduced a regression of the determinants of Sa. . .

Regression Equation, Regression Analysis

# 550 :: 12/12/08
Question 550 has been Answered
Jeff, I am working Trend lines for yearly data and I can't figure this step: trend line is Tt=22.6+0.45 t to generate yearly forecast. Trend line beg. . .

Trend Line

# 551 :: 12/12/08
Question 551 has been Answered
Philadelphia is conducting a study on the characteristics of tourists who drive to Eagles football games. Previous studies indicate that approximately. . .

Sample Size, Confidence Intervals, Proportion

# 555 :: 12/14/08
Question 555 has been Answered
Complete the following: a. Select a variable. Compare the mean of the variable for a sample of 30 for one group with the mean of the variable for a . . .

2-sample t-test, 2-proportion test, 2-sample z-test, z-test

# 557 :: 12/16/08
Question 557 has been Answered
Find the margin or error for the 95% confidence interval used to estimate the population proportion. In a survey of 7100 TV viewers, 38% said they wa. . .

Confidence Intervals, Margin of Error

# 558 :: 12/16/08
Question 558 has been Answered
If Z is a standard normal variable, find the probability that z lies between 0.73 and 1.88 or P(0.73

Area between, Z-Score

# 559 :: 12/16/08
Question 559 has been Answered
The serum cholesterol levels for men in one age group are normally distributed with a mean of 185.1 and a standard deviation of 37.8. All units are i. . .

Area between, Z-Score

# 560 :: 12/17/08
Question 560 has been Answered
Throughout history 55% of registered voters actually have cast a ballot. What is the probability that among a group of 28 students who are registered. . .

BINOMDIST, Binomial cdf, Compliment Rule

# 562 :: 12/17/08
Question 562 has been Answered
Why does the main factor MSs in 2 way ANOVA sometimes carry along interaction effect?. . .

ANOVA, 2-Way ANOVA

# 563 :: 12/19/08
Question 563 has been Answered
A vinyl siding company claims that the mean time to install siding on a medium-size house is at most 20 hours with a standard deviation of 3.7 hours. . . .

1-sample Z-test, 1-sample t-test

# 564 :: 12/19/08
Question 564 has been Answered
For each of the following situations, indicate whether an error has occurred and, if so, indicate what kind of error (Type I or Type II) has occurred.. . .

Type I Error, Type II Error, Power, Hypothesis Test

# 565 :: 12/19/08
Question 565 has been Answered
The coefficient of correlation between two variables X and Y was computed to be {0.60. This means a. the coefficient of determination is 0. b. a. . .

Correlation, coefficient of determination

# 566 :: 12/19/08
Question 566 has been Answered
In an ANOVA test there are 5 observations in each of three treatments. The degrees of freedom in the numerator and denominator respectively are: a. . . .

ANOVA, Degrees of Freedom

# 568 :: 12/21/08
Question 568 has been Answered
16 (a) Plot the data on U.S. general aviation shipments. (b) Describe the pattern and discuss possible causes. (c) Would a fitted trend be helpful? Ex. . .

Trend Line, Linear Regression

# 569 :: 12/21/08
Question 569 has been Answered
Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are all. . .

1-sample t-test, TDIST

# 570 :: 1/7/09
Question 570 has been Answered
How can a t test be employed in hypothesis testing by the use of directional versus nondirectional hypothesis. . .

directional test, 1-tailed test

# 571 :: 1/10/09
Question 571 has been Answered
Dr Zak developed a test to measure depression. He sampled 100 university students to take his five item test. The group of students was comprised of 3. . .

Z-Score, Standard Score

# 572 :: 1/13/09
Question 572 has been Answered
At one university, students are given z-scores at the end of the semester rather than the traditional GPAs. The mean and standard deviation of all stu. . .

Empirical Rule, Z-Score

# 574 :: 1/14/09
Question 574 has been Answered
Assume you have the following data: Ho mu = 200, s = 30, n = 64, and x-bar = 218. Conduct a hypothesis test at the .05 significance level. Assum. . .

1-sample t-test, 1-sample Z-test

# 576 :: 1/16/09
Question 576 has been Answered
TRUE or FALSE The level of significance is the probability that a true hypothesis is rejected. A Type one error is also referred to as an alpha r. . .

Hypothesis Test, Alternative Hypothesis , Alpha, Null Hypothesis

# 580 :: 1/21/09
Conduct the equivalent, nonparametric test of hypothesis using the 5-step process. MLB � Higher Salaries equate to more home runs per team (Using . . .

# 581 :: 1/21/09
hi, I hope you can help me ? I have 30 variables that i wanted to sort them under 5 known groups . the data came from interviews where i collected . . .

# 587 :: 1/26/09
Question 587 has been Answered
True or False Generally speaking, the Null Hypothesis is set up for the purpose of either accepting or rejecting it. If the Null Hypothesis is fal. . .

Null Hypothesis , Alternative Hypothesis

# 588 :: 1/26/09
Question 588 has been Answered
An aptitude test has a mean of 220 and standard deviation of 10. find the corresponding z score for: a) a test score of 232. . .

Z-Score

# 589 :: 1/26/09
Question 589 has been Answered
Apply the Law of Large Numbers: Explain how the following scenario is possible using a coin toss and fictitious data: As the number of trials increase. . .

Law of Large Numbers

# 597 :: 1/30/09
Question 597 has been Answered
TRUE OR FALSE 1. ANOVA is used when we want to know if more than two population means are equal. 2. The sum of the squares error measures the vari. . .

ANOVA

# 599 :: 1/30/09
Question 599 has been Answered
There are two major tests of readiness for college, the ACT and the SAT. ACT scores are reported on a scale from 1 to 36. The distribution of ACT scor. . .

Z-Score, SAT Scores, ACT Scores

# 600 :: 1/30/09
Question 600 has been Answered
True or False The moving average method averages out cyclical and irregular components. When using Chi Square , the sum of the expected freque. . .

ANOVA, Chi-Square, Goodnees of Fit, F distribution

# 611 :: 2/5/09
Question 611 has been Answered
6.) For the following set of data, find the linear regression equation for predicting Y from X: X Y 0 9 . . .

Regression Equation

# 613 :: 2/7/09
Question 613 has been Answered
I am confused on how to calculate a z-score. I am doing a six sigma project right now and am lost on doing the z-score. Here is the information I am p. . .

Z-Score

# 616 :: 2/7/09
Question 616 has been Answered
Evolutionary theories often emphasize that humans have adapted to their physical environment. One such theory hypothesizes that people should spontane. . .

1-sample t-test

# 618 :: 2/8/09
Question 618 has been Answered
Individual scores of a placement examination are normally distributed with a mean of 84.2 and a standard deviation of 12.8. If a random sample of s. . .

Z-Score, t-score

# 619 :: 2/8/09
Question 619 has been Answered
Suppose the annual consumption of chicken mean is 20.84 pounds per person, and that the standard deviation for the consumption of chicken per person i. . .

Central Limit Theorem

# 620 :: 2/8/09
Question 620 has been Answered
The total area under the curve of the standard normal distribution is not necessarily 1.0. A) True B) False. . .

Normal Curve, Standard Normal Distribution, Standard Normal Curve

# 621 :: 2/8/09
Question 621 has been Answered
Consider a sample with data values of 10,20,12,17, and 16. Compute the z-score for each of the five observations. . .

Z-Score

# 622 :: 2/9/09
Question 622 has been Answered
1. If the daily stock price, x, of United Technology is normally distributed with mean 6.56 and standard deviation 2.4, calculate the probability that. . .

# 623 :: 2/9/09
Question 623 has been Answered
The following table lists the number of U.S. mainland hurricane strikes (from 1900 to 1996) for various intensities according to the Saffir-Simpson Hu. . .

Random Variable, Probability Distribution

# 625 :: 2/11/09
Question 625 has been Answered
Mean output of solar cells of three types are measured six times under random light intensity over a period of 5 minutes, yielding the results shown. . . .

ANOVA

# 626 :: 2/15/09
Greetings, My name is Dave Thompson and I work with the Conasauga Drug Court Treatment program in Dalton, GA. I am a Field Practicum Instructor f. . .

# 627 :: 2/16/09
I have two questions. Thanks for answering them. (1)A sports enthusiast created an equation to predict Victories (the teams number of victories in. . .

# 628 :: 2/16/09
I have a standard normal distribution with Mean 130, Stdev 8 for school X and a normal distribution for 120 and 10 for school Y. If we select 1 studen. . .

# 629 :: 2/17/09
Question 629 has been Answered
The following data show samples of three chain stores in three different locations in one town and the amount of dollars spent per customer per visit.. . .

ANOVA

# 630 :: 2/19/09
Question 630 has been Answered
Pretend that you are a Finance person in a large dynamic company. Your dream is to become CFO someday, so you want to make good financial decisions. Y. . .

# 631 :: 2/19/09
Question 631 has been Answered
My company has been arguing over this topic for quite a while, and I'm looking to put an end to this mathematical question. We are an ad agency who. . .

A/B Testing, Response Rates

# 632 :: 2/19/09
Question 632 has been Answered
An automobile manufacturer wants to estimate the mean gasoline mileage that its customers will obtain with its new compact model. How many sample runs. . .

Sample Size, Margin of Error

# 633 :: 2/20/09
Question 633 has been Answered
Roadmarking shall be determined by the retroreflectivity performance of glass beads in the road marking. The roadmarking average level of reflectivity. . .

# 634 :: 2/20/09
Question 634 has been Answered
A contractor is responsible for drainage network cleaning and shall ensure that the required level of service is achieved. The required level of servi. . .

1-Sample Proportion Test

# 635 :: 2/22/09
Question 635 has been Answered
Linemarking for parking bays shall be determined by the retroreflectivity performance of glass beads in the linemarking. The linemarking average level. . .

1-sample t-test, Confidence Intervals

# 637 :: 2/22/09
Question 637 has been Answered
Hi Jeff thanks for all your help so far, your answers have been great and very timely. It is great to be able have help from someone with great profes. . .

Adjusted Wald, Confidence Intervals

# 638 :: 2/23/09
Question 638 has been Answered
To test the null hypothesis that the mean waist size for males under 40 years equals 34 inches versus the hypothesis that the mean differs from 34, th. . .

1-sample t-test

# 639 :: 2/28/09
Question 639 has been Answered
CherryBerry Soda, Inc. claims that 15 percent of the population can identify its products. In efforts to boost their identity, CherryBerry employs a f. . .

Normal Approximation to Binomial , 1-Proportion Test

# 641 :: 3/2/09
Question 641 has been Answered
In general, what is a Critical Value or Cut-Off Score of a test statistic. . .

Critical Value, test statistic

# 642 :: 3/2/09
Question 642 has been Answered
You are a purchasing agent at a major manufacturing company. You have several hundred business cards from sales reps who have visited you, and you ha. . .

# 644 :: 3/3/09
Question 644 has been Answered
An aptitude test has a mean of 220 and standard deviation of 10. find the corresponding z score for: a) a test score of 232 b) a test score of 212. . .

Z-Score

# 648 :: 3/7/09
Question 648 has been Answered
A financial planner wants to compare the yield of income- and growth-oriented mutual funds. Fifty thousand dollars is invested in each of a sample of. . .

# 650 :: 3/9/09
Question 650 has been Answered
2. Your company makes ice cream (178 flavors!) and has just acquired a distribution company with lots of ice cream trucks. You will use their trucks. . .

# 651 :: 3/9/09
Question 651 has been Answered
For a population with a mean of 80 and standard deviation of 12, what is the z-score corresponding to x=71?. . .

# 653 :: 3/11/09
Question 653 has been Answered
What is the cost of a telephone call (per dollar) using a calling card that follows the formula below for a 20-minute call. Cost = 0.50 + 0.15 Minute. . .

# 657 :: 3/18/09
Question 657 has been Answered
If events A and B are not mutually exclusive, they may be either independent or dependent. A) True B) False. . .

# 658 :: 3/18/09
Question 658 has been Answered
Under certain conditions, it is possible that the sum of the probabilities of all the sample points in a sample space is less than one. A) Tru. . .

# 659 :: 3/18/09
Question 659 has been Answered
Suppose that A and B are mutually exclusive events, and that P(A) = 0.4 and P(B) = 0.3. Then, P(A and B) will be: A) 0.0 B) 0.4 C) 0.3 D) 0.7. . .

# 660 :: 3/18/09
Question 660 has been Answered
Four cards are selected, one at a time, from a standard deck of 52 cards. Let x represent the number of aces drawn in a set of 4 cards. If this expe. . .

Binomial Probability

# 661 :: 3/19/09
Question 661 has been Answered
A student is taking a 10 question multiple choice quiz. There are four possible answers to each question. The student decides to guess at random on al. . .

BINOMDIST

# 662 :: 3/23/09
Question 662 has been Answered
I need the formula to calculate z-score. My input is: Base Sample Size, Target Sample Size, Base Proportion, Target Proportion. I have a calculator . . .

2-proportion test

# 663 :: 4/11/09
Question 663 has been Answered
When we reject the null hypothesis, we are certain that the null hypothesis is false. A) True B) False. . .

Null Hypothesis

# 664 :: 4/11/09
Question 664 has been Answered
If our decision in a hypothesis test is to fail to reject the null hypothesis, then we know that the null hypothesis must be true. A) True . . .

Null Hypothesis

# 667 :: 4/11/09
Question 667 has been Answered
If the p-value is greater than the level of significance α , then the decision must be to reject Ho. A) True B) False. . .

p-value, Hypothesis Test

# 668 :: 4/13/09
Question 668 has been Answered
Which of the following is the probability of making a Type I error? A) α B) 1 - α C) β D) 1 - β. . .

Type I Error, Type II Error

# 669 :: 4/13/09
Question 669 has been Answered
You have failed to reject the null hypothesis when it is false, and therefore you have made a A) Type A correct decision. B) Type B corr. . .

Type I Error, Type II Error, Hypothesis Test

# 670 :: 4/13/09
Question 670 has been Answered
Assume that z is the test statistic and calculate the value of z∗ for testing the null hypothesis Ho: μ =150.0 when σ = 4.5, n=15, x(b. . .

test statistic, z-test

# 671 :: 4/13/09
Question 671 has been Answered
A statistician was testing the following hypotheses: Ho: μ = 500 vs. Ha: μ ≠ 500. The p-value approach was to be used. A sample . . .

# 672 :: 4/13/09
Question 672 has been Answered
In Meijer supermarket, the customer's waiting time to check out is approximately normally distributed with a standard deviation of 2.5 minutes. A samp. . .

Hypothesis Test

# 673 :: 4/16/09
Question 673 has been Answered
Classify the following as independent or dependent samples: a. Weights of identical twins b. The effectiveness of two different brands of ibuprofen. . .

Dependent Sample, Independent Sample

# 674 :: 4/17/09
Question 674 has been Answered
In what ways is the t distribution similar to the standard normal distribution? In what ways is the t distribution different from the standard normal . . .

t-distribution, Standard Normal Distribution

# 675 :: 4/17/09
Question 675 has been Answered
A group of sheep, infested with tapeworms, are randomly divided into two groups as follows. Each sheep is assigned a number (1 through 20) and then 10. . .

Dependent Sample, Independent Sample

# 676 :: 4/17/09
Question 676 has been Answered
Consider testing Ho: μd ≤ 0 vs. Ha: μd = > 0 with n =20 and t∗ =1.95. Place bounds on the p-value using the table of critical. . .

Student-t, Students t-distribution, Critical Value

# 677 :: 4/17/09
Question 677 has been Answered
A random sample of 51 observations was selected from a normally distributed population. The sample mean was x = 88.6 , and the sample variance was s2 . . .

Chi-Square, Standard Deviation, Population Standard Deviation, sample variance, sampe standard deviation

# 678 :: 4/17/09
Question 678 has been Answered
A particular candidate claims she has the support of at least 60% of the voters in her district. A random sample of 150 voters yields 87 who support h. . .

test statistic, Normal Approximation to Binomial

# 679 :: 4/17/09
Question 679 has been Answered
State the null hypothesis, Ho,and the alternative hypothesis, Ha , that would be used to test the claim: The standard deviation has increased from its. . .

Null Hypothesis , Alternative Hypothesis

# 680 :: 4/17/09
Question 680 has been Answered
To test the null hypothesis that the mean waist size for males under 40 years equals 34 inches versus the hypothesis that the mean differs from 34, th. . .

test statistic

# 681 :: 4/17/09
Question 681 has been Answered
If two independent samples are used in a hypothesis test concerning the difference between population means for which the combined degrees of freedom . . .

Degrees of Freedom

# 682 :: 4/17/09
Question 682 has been Answered
Explain the difference between testing a single mean and testing the difference between two means. What two assumptions must be met when one is using . . .

Difference between means

# 683 :: 4/18/09
Question 683 has been Answered
A baseball fan would like to estimate the mean time it takes to complete a major league baseball game. He randomly selects 40 game lengths (times to c. . .

Confidence Intervals

# 684 :: 4/18/09
Question 684 has been Answered
Tax companies imply that the returns they prepare are perfect, but what proportion of returns from tax companies have mistakes? To answer this questio. . .

Confidence Intervals, Confidence Interval around a Proportion

# 685 :: 4/18/09
Question 685 has been Answered
NKU needs to estimate the mean number of hours that all students work to earn money, on average, per week during the full semesters (fall and spring).. . .

Sample Size, Margin of Error

# 686 :: 4/18/09
Question 686 has been Answered
A label on a container of orange juice claims that the orange juice contains an average of 2 grams of fat with standard deviation of 1.5 grams. A cons. . .

1-sample Z-test

# 687 :: 4/18/09
Question 687 has been Answered
I would like to determine whether Meijer or Kroger has lower prices on average for families. I randomly speak with 100 customers who are purchasing g. . .

Independent Sample

# 689 :: 4/20/09
Accounting procedures allow a business to evaluate their inventory at LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated. . .

Paired t-test

# 691 :: 4/21/09
Question 691 has been Answered
Calculate the Standard Deviation of the following list of data: 6, 7, 8, 9, 10. . .

Standard Deviation

# 692 :: 4/21/09
Question 692 has been Answered
Create a Histogram of the following data: Interval Frequency 0 - 5 0 5 - 10 5 10 - 15 5 15 - 20 15 20 - 25 5 25 . . .

# 693 :: 4/21/09
Question 693 has been Answered
Given a single deck of cards, what is the probability of drawing either a king or a diamond? Hint - There are four kings in a deck and 13 diamonds. T. . .

Union, Probability, Joint Probability

# 694 :: 4/21/09
Suppose you conduct a study and find that the probability of having a baby boy is 60%. Now suppose three of your relatives are going to have babies. . . .

# 695 :: 4/24/09
Question 695 has been Answered
I need help with the following. (A) Develop one business research question (B) Formulate a research hypothesis to test one population parameter an. . .

Parameter

# 697 :: 4/25/09
Question 697 has been Answered
A random sample of 30 executives from companies with assets over $1 million was selected and asked for their annual income and level of education. Th. . .

ANOVA, Seasonal Data

# 698 :: 4/26/09
Question 698 has been Answered
A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were 3.087. . .

# 699 :: 4/26/09
Question 699 has been Answered
1) The following are the first Quiz scores from a previous RES 341 class: 9.5, 7.5, 9.5, 7, 10, 7.5, 6.5, 1.5, 8, 10 A. Is this data discrete or co. . .

Continuous Data

# 700 :: 4/26/09
Question 700 has been Answered
2) Assume the following summary statistics, which describe the speed of a computer processor, are available from a sample of Intel Pentium IV chips ma. . .

Chebyshev's Theorem

# 701 :: 4/26/09
Question 701 has been Answered
A local bakery determines that the probability of a customer ordering a blueberry muffin is 50%. 5 customers come into the bakery. A. What is the pr. . .

BINOMDIST, Binomial pmf, Binomial Probability

# 702 :: 4/26/09
Question 702 has been Answered
A random sample of 100 students who took a statistics exam were asked their score on the exam. The mean score on the test was 50; the standard deviat. . .

Z-Score, Area between

# 703 :: 4/26/09
Question 703 has been Answered
The following data is a random sample of 1st quiz scores from previous Research 342 classes. 9.5, 6.5, 4.25, 8.5, 7.5, 4.5, 4.25, 6, 7 mean = 6.44 . . .

Confidence Intervals

# 705 :: 4/27/09
THIS QUESTION IS NO LONGER AVAILABLE. . .

1-sample Z-test

# 706 :: 4/28/09
Question 706 has been Answered
What is a chi-squared test used for? What is the typical null and alternate hypothesis when doing a chi-squared test?. . .

Chi-Square

# 707 :: 4/29/09
Question 707 has been Answered
Would you be able to assist me in completing a 5 step hypothesis test on both hypotheses (1 parameter & another with 2 or more)? In completing this t. . .

Five Step Hypothesis Testing, Parameter

# 708 :: 4/30/09
Question 708 has been Answered
Standardized scores offers a way of comparing norm-referenced scores. The z-score distribution is based on knowing how many standard deviations away f. . .

Z-Score, t-score, Percentile Rank

# 709 :: 4/30/09
Question 709 has been Answered
Discuss which analysis of variance should be applied when an experiment has more than one independent variable. Discuss the assumptions and limitation. . .

ANOVA, Factorial ANOVA, 2-Way ANOVA

# 710 :: 4/30/09
Question 710 has been Answered
Discuss how the statistical application of Pearson r is used for hypothesis testing. Through application of the Spearman Correlation discuss what typ. . .

Correlation, Pearson r, Spearman Correlation

# 711 :: 5/3/09
Question 711 has been Answered
Four research participants take a test of manual dexterity (high scores mean better dexterity) and an anxiety test (high scores mean more anxiety). Th. . .

# 712 :: 5/3/09
Question 712 has been Answered
Make up a scatter diagram with 10 dots for each of the following situations: (a) perfect positive linear correlation, (b) large but not perfect positi. . .

Scatter Diagram, Correlation, Curvilinear Correlation

# 713 :: 5/3/09
Question 713 has been Answered
Do students at various colleges differ in how sociable they are? Twenty-five students were randomly selected from each of three colleges in a particul. . .

ANOVA, Eta-Squared, Effect Size, ANOVA Summary Data

# 714 :: 5/5/09
Question 714 has been Answered
The mean score on a math test at milby high school was 50. the standard deviation was 10. If the same test was administered to the entire school distr. . .

Z-Score

# 715 :: 5/5/09
Question 715 has been Answered
university of texas will accept all students that have a GPA in the top 10% at their school. At yates the school GPA average is 3.0(on a 4.0 scale) wi. . .

Z-Score

# 716 :: 5/5/09
Question 716 has been Answered
The rockets are playing Lakers tonight in basketball. The lakers average 90 points a game, with a SD of 10. What would the rockets need to score to be. . .

Z-Score

# 718 :: 5/5/09
Question 718 has been Answered
The state of Texas college admission board has set a standard for automatic acceptances to any university at top 10% of any graduating class will be a. . .

Z-Score

# 720 :: 5/5/09
Question 720 has been Answered
City Opera, a local opera company, wishes to take a sample of its subscribers to learn the average number of years people have been subscribing. The d. . .

Sample Size

# 721 :: 5/5/09
Question 721 has been Answered
What does regression do? What is its purpose?. . .

Regression Analysis

# 722 :: 5/5/09
Question 722 has been Answered
What is the definition of an "independent" variable? A dependent variable? What about a variable I intend to use to help do some forecasting. Int. . .

Scatter Plot, Scatter Diagram, Independent Variable, Dependent Variable

# 723 :: 5/5/09
Question 723 has been Answered
Using this research question and data, perform a nonparametric hypothesis test (Part A and B). Research Question: Is the average age greater than 4. . .

Sign Test, Mann Whitney

# 727 :: 5/23/09
Question 727 has been Answered
Interpret the following table showing the percentage of individuals on a low-fat or low-cholesterol diet by gender and age. Age Group Women. . .

# 728 :: 5/23/09
Question 728 has been Answered
What hypothesis testing model (my models handout) would be used under each of the following conditions. Use the model number from my handout if y. . .

Statistical Model, test statistic

# 729 :: 5/23/09
Question 729 has been Answered
I want to prove that a population mean is not 150. Use an alpha of 5% and set up the full, detailed, five step hypothesis test. Assume when the sampl. . .

1-sample t-test

# 730 :: 5/23/09
Question 730 has been Answered
Describe the steps in formal hypothesis testing. Make at least one comment for each step.. . .

Steps in Hypothesis Test, Hypothesis Test

# 731 :: 5/23/09
Question 731 has been Answered
Test to see if four population means are the same or different. Assume the populations are normally distributed and have equal variances. Use the fo. . .

ANOVA Summary Data

# 732 :: 5/23/09
Question 732 has been Answered
You have asked to research the high absenteeism rate in your company. One required analysis is to be by gender. Assume you have been asked to do the . . .

# 733 :: 5/24/09
Question 733 has been Answered
The data in the following tables are some of the results of an Internal Revenue Service survey of taxpayers. Analyze and interpret the data. -The las. . .

# 735 :: 5/25/09
Question 735 has been Answered
how does a confidence interval this relate to learning statistics How do you think confidence intervals are useful in the real-world?. . .

Confidence Intervals

# 736 :: 5/28/09
Question 736 has been Answered
A student heard that the average household watches 26.4 hours of t.v. per week, with a stand.dev. of 2.3 hours. He decided to run his own experiment . . .

1-sample Z-test

# 737 :: 5/31/09
Question 737 has been Answered
(a) Choose one beverage category and plot the data (MILK CATAGORY CHOSEN). (b) Describe the trend (if any) and discuss possible causes. (c) Would a f. . .

Time-Series

# 738 :: 6/4/09
Question 738 has been Answered
What value would be needed to complete the following probability distribution? x p (x) 0 . . .

Random Variable, Expected Value

# 739 :: 6/4/09
Question 739 has been Answered
How many data do we need as a minimum in order to calculate the z-score meaningfully?. . .

Z-Score

# 740 :: 6/6/09
Question 740 has been Answered
After a bumper crop, a mushroom grower hypothesizes that mushrooms will remain at the average wholesale price of $1 per pound. State the null hypothes. . .

# 741 :: 6/6/09
Question 741 has been Answered
Assume you have the following data: Ho: u = 200, S = 30, n = 64, and X = 218. Conduct a two-tailed hypothesis test at the .05 significance level.. . .

1-sample Z-test

# 743 :: 6/6/09
Question 743 has been Answered
Assume you have the following data: Ho: u = 2,450, S = 400, n = 100, and X = 2,300. Conduct a hypothesis test at the .01 significance level. **If the. . .

1-sample Z-test

# 744 :: 6/6/09
Question 744 has been Answered
Quality Motors is an automobile dealership that regularly advertises in its local market area. It claims that a certain make and model of car averages. . .

1-sample t-test

# 745 :: 6/8/09
Calculate the average student score necessary for the district to retain its federal funding. You may assume that the Standard Deviation will not chan. . .

# 746 :: 6/12/09
a. Select a variable. Compare the mean of the variable for a sample of 30 for one group with the mean of the variable for a sample of 30 for a second . . .

# 747 :: 6/13/09
A random sample of 46 observations was selected from a normally distributed population. The sample mean was xbar=81, and the sample variance was s2=3. . .

# 748 :: 6/14/09
What test of differences is appropriate in each of the following situations? Why? (a) Average campaign contributions of Democrats, Republicans, and. . .

# 749 :: 6/14/09
Question 749 has been Answered
A personnel manager has a computer-generated list of all employees that indicates that 70 percent are full-time employees, 20 percent are part-time em. . .

Chi-Square Goodnes of Fit Test

# 750 :: 6/14/09
Question 750 has been Answered
Test the hypothesis of no differences for average payback period (years) necessary to justify solar heating systems for residences. Savings and Loa. . .

# 751 :: 6/14/09
Question 751 has been Answered
The managers in a companys East and West regions were rated on the basis of the companys evaluation system. A researcher wishes to conduct a t-test . . .

2-sample t-test

# 752 :: 6/14/09
Question 752 has been Answered
An Excel Spreadsheet is reprinted below. Interpret the t-test results. Are they statistically significant? t-Test: Paired Two Sample for Means Be. . .

Paired t-test

# 753 :: 6/14/09
Perform a chi-square test on the following data: (a) Regulation is the best way to ensure a safe workplace. . . .

# 754 :: 6/14/09
Question 754 has been Answered
Collapse the response categories in the following table so that it meets the assumption of the chi-square test; then perform the test. . . .

Chi-Square Test of Independence

# 755 :: 6/14/09
Question 755 has been Answered
Interpret the following SPSS computer output for the chi-square test. Variable COMMUTE is How did you get to work last week? Variable GENDER is Are. . .

Chi-Square Test of Independence, SPSS

# 756 :: 6/15/09
In Dallas some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made. . .

# 758 :: 6/15/09
To test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were hande. . .

# 759 :: 6/15/09
A sample of 25 concession stand purchases at the May 12 matinee of Spider-Man 3 showed a mean purchase of $ 7.29 with a standard deviation of $ 3.02. . . .

# 760 :: 6/17/09
. You are a researcher who conducted a study of soft-drink preferences among residents in a test market prior to an advertising campaign for a new co. . .

# 761 :: 6/18/09
I need to know which formulas would be used to answer these two probability questions. 1. A certain airplane has two independent alternators to prov. . .

# 762 :: 6/18/09
Bob enjoys making candy and some friends have encouraged him to open a candy-making business. To see if the local citizens buy enough candy, Bob gath. . .

# 763 :: 6/18/09
Finding appropriate z- and t-scores is important when constructing confidence intervals. Confidence intervals allow one to estimate important populat. . .

# 764 :: 6/23/09
Question 764 has been Answered
Suppose Abraham Lincoln had answered a survey questionnaire in which he indicated that he had not received a grade school diploma. The researcher foun. . .

Correlation

# 765 :: 6/23/09
Question 765 has been Answered
A football team's season ticket sales, percentage of games won, and number of active alumni for the years 1992-2000 are given below: Year . . .

Regression Analysis

# 766 :: 6/23/09
Question 766 has been Answered
A researcher has a series of Likert-scaled items and a measure of frequency of absenteeism. He uses each of the Likert-scaled items in a separate biva. . .

Correlation, Non-Linear Correlation

# 767 :: 6/24/09
Question 767 has been Answered
IQ scores are normally distributed with a mean of 100 and a std dev of 15. If 25 people are randomly selected for an IQ test, find the probably that . . .

Z-Score

# 768 :: 6/26/09
Question 768 has been Answered
A multiple choice test consists of 25 questions with possible answers of a, b, c, d, and e. Estimate the probability that with random guessing, the nu. . .

Binomial pmf

# 770 :: 6/29/09
Question 770 has been Answered
Dr. Stallter has been teaching basic statistics for many years. She knows that 80 percent of the students will complete the assigned problems. She has. . .

Bayes Theorem , Tree Diagram

# 771 :: 6/29/09
Question 771 has been Answered
One-fourth of the residents of the Burning Ridge Estates leave their garage doors open when they are away from home. The local chief of police estimat. . .

Bayes Theorem , Conditional Probability, Tree Diagram

# 772 :: 6/29/09
A random sample of 16 pharmacy customers showed the waiting times below (in minutes). Find a 90 percent confidence interval for μ, assuming that the . . .

# 773 :: 7/1/09
i have problem in run multiple linear regression which faced me a problem of heteroscadecity and i want solve it using weight least squares (wls) but . . .

# 774 :: 7/5/09
Question 774 has been Answered
If I'm doing a multivariate linear regression in Minitab (about 40 variables), how to restrict all coefficients positive?. . .

Linear Regression

# 775 :: 7/6/09
Question 775 has been Answered
1.-A state meat inspector in Iowa has been given the assignment of estimating the mean net weight of packages of ground chuck labeled 3 pounds. Of c. . .

Confidence Intervals

# 776 :: 7/8/09
Question 776 has been Answered
Clients at a Diabetic Education Program were randomly assigned to one of two learning programs. Group A participants attended a three-day, in-class. . .

# 777 :: 7/11/09
Suppose that the quarterly sales levels among health care information systems companies are approximately normally distributed with a mean of million. . .

# 778 :: 7/12/09
Question 778 has been Answered
200 students took a test. The scores were normally distributed. Your score was in the 60th percentile. How many people scored at or below your score?. . .

Percentile

# 779 :: 7/13/09
Question 779 has been Answered
If all the values in a set are converted to z-scores, is the shape of the distribution of the z scores will be bell shape regardless of the distributi. . .

Central Limit Theorem

# 780 :: 7/14/09
Question 780 has been Answered
Dear Mr. Sauro: In reference to you article, "Calculating a Sigma Level from Task Success," I found no references to usability nor task completio. . .

Usability, Six Sigma

# 781 :: 7/14/09
Question 781 has been Answered
I am to do a study that involves people whose IQ are in the normal range 70 to 130. How many people must I screen with IQ test in order to find a samp. . .

Sample Size

# 782 :: 7/14/09
Question 782 has been Answered
A 20-minute consumer survey mailed to 500 adults aged 2534 included a $5 Starbucks gift certificate. The same survey was mailed to 500 adults aged 2. . .

2-proportion test

# 784 :: 7/21/09
Question 784 has been Answered
Two manufacturing facilities produce 1280 1024 LED (light-emitting diode) displays. Twelve displays are chosen at random from each lab, and the num. . .

Mann Whitney

# 786 :: 7/27/09
Question 786 has been Answered
From her firms computer telephone log, an executive found that the mean length of 64 telephone calls during July was 4.48 minutes with a standard de. . .

2-sample t-test

# 787 :: 7/30/09
Question 787 has been Answered
Below are fertility rates (average children born per woman) in 15 EU nations for 2 years. (a) Make a scatter plot. (b) Find the correlation coefficie. . .

correlation coefficient , significant correlation, Pearson r

# 788 :: 7/31/09
A recent survey of 50 executives who were laid off from their previous position revealed it took a mean of 26 weeks for them to find another position.. . .

# 789 :: 7/31/09
A state meat inspector in Iowa has been given the assignment of estimating the mean net weight of packages of ground chuck labeled 3 pounds. Of cour. . .

# 790 :: 7/31/09
As a condition of employment, Fashion Industries applicants must pass a drug test. Of the last 220 applicants 14 failed the test. Develop a 99 percent. . .

# 791 :: 8/4/09
Question 791 has been Answered
Serum cholesterol levels were taken from a population of 10,000 college students. The results were normally distributed. Males had a mean of 195 and a. . .

Z-Score

# 792 :: 8/7/09
send the standard normal table. . .

# 793 :: 8/8/09
Question 793 has been Answered
For the total population of a large southern city, mean family income is $34000, with a standard deviation (for the population) of $5000. a. imagi. . .

Z-Score

# 794 :: 8/10/09
Question 794 has been Answered
A psychologist has developed a test to measure self-control. The test is normed so that it has a mean of 100 and a standard deviation of 15... The s. . .

Z-Score, Percent Score, Percentile Rank, Area between

# 795 :: 8/13/09
Question 795 has been Answered
Data from the MTF 2006 survey reveal that 71.5% (432 out of 604) of males and 74% (562 out of 756) of females reported trying alcohol. You wonder whe. . .

2-proportion test

# 796 :: 8/13/09
Question 796 has been Answered
Very happy Not happy at all Mean ideal number of children 3.32 2.07 Standard deviation . . .

2-sample t-test

# 797 :: 8/15/09
Question 797 has been Answered
The issue of how much should be spent to solve particular U.S. social problems is a complex matter, and people have diverse and conflicting ideas on t. . .

Chi-Square

# 798 :: 8/19/09
Question 798 has been Answered
Teens were asked in the MTF 2006 survey how often they think about social issues (specific issues were not identified). The bivariate table includes r. . .

Chi-Square, Chi-Square Test of Independence

# 802 :: 8/27/09
Question 802 has been Answered
type of research where using the t statistic may be an appropriate alternative to using a z-score. . .

t statistic

# 803 :: 8/28/09
Question 803 has been Answered
In a study, the sum of squared deviations from the mean for the sample is 12 and there are 4 participants. What is the estimated population variance?. . .

Variance

# 804 :: 8/29/09
Question 804 has been Answered
The mean on this test is 3.5 with a standard deviation of .5. Sally scores 1.5 on this test. How many standard deviations is Sally from the mean?. . .

Z-Score

# 806 :: 9/7/09
Question 806 has been Answered
Discuss how the statistical application of Pearson r is used for hypothesis testing.l Through application of the Spearman Correlation discuss what ty. . .

Pearson r, Spearman Correlation

# 811 :: 10/1/09
Discuss the assumptions for using a chi-square test. Research articles using and provide practical examples from the reseach to support your assumptio. . .

# 812 :: 10/2/09
Question 812 has been Answered
A Tamiami shearing machine is producing 10 percent defective pieces, which is abnormally high. The quality control engineer has been checking the outp. . .

BINOMDIST, Binomial Probability

# 813 :: 10/2/09
Question 813 has been Answered
Serum cholesterol levels were taken from a population of 10,000 college students. The results were normally distributed. Males had a mean of 195 and a. . .

Z-Score, NORMSDIST

# 814 :: 10/4/09
Question 814 has been Answered
in a school how is ztest used in time table ... one group that studies 7 periods a day of 45 mins each class and the other group can choose semester w. . .

2-sample z-test, 2-sample t-test

# 815 :: 10/5/09
Question 815 has been Answered
Shaver Manufacturing, Inc., offers dental insurance to its employees. A recent study by the human resource director shows the annual cost per employee. . .

Z-Score, Area between

# 817 :: 10/8/09
1) Assuming in New York 80% of women and 50% of men know where Tiffany is. At a crossing I ask pedestrians for directions to Tiffany and get these ans. . .

Binomial Probability

# 819 :: 10/15/09
Question 819 has been Answered
For a particular sample of 50 scores on a psychology exam, the following results were obtained. First quartile = 52 Third quartile = 84 Standard dev. . .

Chebyshev's Theorem, Midrange, Empirical Rule

# 820 :: 10/17/09
Question 820 has been Answered
An animal trainer obtained the following sample data (Table A) in a study of reaction times of dogs (in seconds) to a specific stimulus. He then selec. . .

Standard Deviation, Standard Deviation on Frequency Data, Standard Deviation of Grouped Data, F-test

# 821 :: 10/18/09
Question 821 has been Answered
A manufacturer can typically process 176-264 devices a given period of concern. In this situation the processing event is either pass or fail. There i. . .

Power, Sample Size, Effect Size, 1-Proportion Test

# 822 :: 10/19/09
Jeff... the previous answer was not quite the answer I was anticipating- let me restate the problem more clearly. 1. A manufacturer has a process whi. . .

# 823 :: 10/22/09
Question 823 has been Answered
What is an 'effect size' ? When is it used ? Why is it used in educational research?. . .

Effect Size, Cohen d

# 824 :: 11/8/09
Question 824 has been Answered
The grades on a statistics midterm test are normally distributed with a mean of 78 and a standard deviation of 6 a. What proportion of the class has . . .

Z-Score, Standard Error of the Mean

# 830 :: 11/24/09
A psychologist is studying the distribution of IQ scores of girls at an alternative high school. In wishing to estimate the average IQ scores in this . . .

# 831 :: 12/3/09
I have a humor appreciation survey with 40 items and 500 participants. The items were interpreted and classified by a theory into four classes of 10 i. . .

# 832 :: 12/8/09
1.What are the underlying assumptions of Spearman rank-order scale? 2.What happens when a stanine is more than 9?Explain.. . .

# 833 :: 12/9/09
Question 833 has been Answered
suppose that the census indicates the average American earns $36,345.45 per year. You are interested in the whether people who majored in political s. . .

Hypothesis Test, 1-sample t-test

# 834 :: 12/9/09
Question 834 has been Answered
You are interested in testing the hypothesis that men have greater levels of political participation than women, so you survey 332 men and 375 women . . .

2-sample t-test, Hypothesis Test

# 835 :: 12/12/09
Analyze the following two data sets: o In Statistics Alive, Module 35, p. 410411, data are presented for 15 persons regarding high. . .

# 836 :: 1/13/10
Question 836 has been Answered
a statistician was setting up a hypothesis test with a level of significance dictated by upper management. However, she was concerned that the test wo. . .

Type II Error, Sample Size

# 838 :: 2/9/10
Question 838 has been Answered
using the full 5-step process test to see if a population mean is not 25. Sample data is: Mean 24, standard deviation 10 and a sample of 400 was taken. . .

1-sample t-test

# 840 :: 2/11/10
Question 840 has been Answered
Sat verbal scores are normally distributed with a mean of 426 and a standard deviation of 94. Use the Empirical Rule to determine what percent of the. . .

Empirical Rule

# 842 :: 2/18/10
Question 842 has been Answered
what statistic method is best used to test 'the influence of persons on behaviour of other persons? thank you.. . .

# 843 :: 2/27/10
Question 843 has been Answered
Braking distances of cars. A random sample of 13 four-cylinder cars is obtained and braking distances are measured and found to have a mean of 137.5 . . .

Standard Deviation, Two Variances, F-statistic

# 844 :: 3/2/10
Question 844 has been Answered
A new weight-watching company, Weight Reducers International, advertises that those who join will lose, on the average, 10 pounds the first two weeks. . .

1-sample t-test, 1-sample Z-test

# 845 :: 3/2/10
Question 845 has been Answered
Dole Pineapple, Inc., is concerned that the 16-ounce can of sliced pineapple is being overfilled. Assume the standard deviation of the process is .03. . .

1-sample t-test, 1-sample Z-test

# 846 :: 3/2/10
Question 846 has been Answered
A recent article in The Wall Street Journal reported that the 30-year mortgage rate is now less than 6 percent. A sample of eight small banks in the . . .

1-sample t-test

# 847 :: 3/5/10
Question 847 has been Answered
Grand Strand Family Medical Center is specifically set up to treat minor medical emergencies for visitors to the Myrtle Beach area. There are two fac. . .

2-sample t-test

# 848 :: 3/5/10
Question 848 has been Answered
The president of the American Insurance Institute wants to compare the yearly costs of auto insurance offered by two leading companies. He selects a . . .

Paired t-test

# 849 :: 3/5/10
Question 849 has been Answered
A real estate agent in the coastal area of Georgia wants to compare the variation in the selling price of homes on the oceanfront with those one to t. . .

F-test

# 850 :: 3/5/10
Question 850 has been Answered
The following is a partial ANOVA table. Source sum of Squares df . . .

ANOVA Table, ANOVA

# 851 :: 3/5/10
Question 851 has been Answered
In a particular market there are three commercial television stations, each with its own evening news program from 6:00 to 6:30 P.M. According to a r. . .

Chi-Square Test of Independence, Chi-Square Goodnes of Fit Test

# 852 :: 3/5/10
Question 852 has been Answered
There are four entrances to the Government Center Building in downtown Philadelphia. The building maintenance supervisor would like to know if the en. . .

Chi-Square Goodnes of Fit Test

# 853 :: 3/6/10
Question 853 has been Answered
A recent study focused on the number of times men and women who live alone buy take-out dinner in a month. The information is summarized below. Stat. . .

2-sample z-test

# 855 :: 3/6/10
Question 855 has been Answered
Random samples of five were selected from each of three populations. The sum of squares total was 100. The sum of squares due to the treatments was 4. . .

ANOVA Summary Data

# 856 :: 3/14/10
Question 856 has been Answered
In this case, we are going to study some data collected from Kelly Blue Book for several hundred 2005 used General Motors (GM) cars. This data allows . . .

Regression Analysis

# 857 :: 3/17/10
Question 857 has been Answered
A drug manufacturing company conducted a survey of customers. The research question is: Is there a significant relationship between packaging preferen. . .

Chi-Square Test of Independence

# 858 :: 3/18/10
Question 858 has been Answered
A questionnaire about study habits was given to a random sample of students taking a large introductory statistics class. The sample of 25 students re. . .

Margin of Error

# 859 :: 3/18/10
Question 859 has been Answered
1) Spinifex pigeons are one of the few bird species that inhabit the desert of Western Australia. The pigeons rely almost entirely on seeds for food. . . .

Confidence Intervals

# 860 :: 3/30/10
Question 860 has been Answered
Problem # 1: Clothing for Runners: Your company sells exercise clothing and equipment on the internet. To design the clothing, you collect a data on. . .

Confidence Intervals, Margin of Error

# 861 :: 4/8/10
Question 861 has been Answered
Lab 6, confidence intervals, two sample and paired In class we discussed GM testing a brake light. Suppose that this is very expensive, time-consum. . .

# 862 :: 4/12/10
Question 862 has been Answered
A recent survey of community colleges found the average age of attending students to be 29. A class of 24 students has a mean age of 26 and a standard. . .

# 863 :: 4/12/10
Describe how measurements and regression analysis are interpretations of reality and not reality itself. (One page answer). . .

# 864 :: 4/15/10
Question 864 has been Answered
1. Suppose a 95% confidence interval for the mean daily sales for a sample of 100 days from an internet site is:($236, $318). a. Will a 99% confidenc. . .

# 866 :: 10/9/10
Question 866 has been Answered
A study showed 118 instances of breast cancer among 3,303 mothers who used diethylstibestrol (DES), an estrogen-like substance formerly used to preven. . .

# 867 :: 10/11/10
A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. An organic candl. . .

# 868 :: 10/14/10
Question 868 has been Answered
Suppose that a 90% confidence interval for a population mean μ is constructed from a sample, resulting in the interval from 120 to 150. What was. . .

Confidence Intervals, Margin of Error

# 869 :: 10/14/10
Question 869 has been Answered
You need to estimate the mean Christmas sales across a large chain of jewelry stores. You want to estimate this mean value to within $100 with 99% co. . .

Sample Size

# 870 :: 11/6/10
Question 870 has been Answered
A hospital in California uses 100.6 degrees Fahrenheit as the lowest temperature considered to indicate a fever. What percentage of normal and health. . .

Z-Score

# 872 :: 12/7/10
Question 872 has been Answered
Discuss how a t Test for a dependent variable can be of great value in applying a new approach to the treatment of aggressive behavior to a small grou. . .

# 873 :: 1/3/11
Question 873 has been Answered
During recent seasons, Major League Baseball has been criticized for the length of the games. A report indicated that the average game lasts 3 hours a. . .

1-sample t-test

# 874 :: 1/3/11
Question 874 has been Answered
Martin Motors has in stock three cars of the same make and model. The president would like to compare the gas consumption of the three cars (labeled c. . .

ANOVA

# 875 :: 1/8/11
Question 875 has been Answered
The amount of income spent on housing is an important component of the cost of living. The total costs of housing for homeowners might include mortgag. . .

Paired t-test

# 876 :: 1/8/11
Question 876 has been Answered
A suburban hotel derives its gross income from its hotel and restaurant operations. The owners are interested in the relationship between the number o. . .

Scatter Plot, correlation coefficient

# 877 :: 1/13/11
Question 877 has been Answered
Suppose that the sales manager of a large automotive parts distributor wants to estimate as early as April the total annual sales of a region. On the. . .

Regression Analysis

# 878 :: 1/16/11
Question 878 has been Answered
Banner Mattress and Furniture Company wishes to study the number of credit applications received per day for the last 300 days. To interpret, there. . .

Chi-Square Goodnes of Fit Test, Poisson Distribution

# 879 :: 3/14/11
What is statistical significance of p-value. . .

# 880 :: 3/24/11
Question 880 has been Answered
Describe the similarities between an F-ratio and a t statistic.. . .

t-statistic, F-statistic

# 881 :: 3/24/11
6. The following data represent the results from an independent-measures study comparing three treatments. a. Compute SS for the set of 3 treatment. . .

# 882 :: 3/24/11
8. For the preceding problem you should find that there are significant differences among the three treatments. The primary reason for the significa. . .

# 883 :: 4/1/11
In studying satisfaction patients have with an operation I have 2 random groups each given a different questionaire. I want to compare the responses o. . .

# 884 :: 5/1/11
1The following data represent the results from an independent-measures study comparing three treatments. Treatment I II III n = 10 n = 10 n = 10 . . .

# 885 :: 5/2/11
as i study on childhood disease then my collected sample is 269 and variable include age of child ,vaccination status , social condition include type . . .

# 886 :: 5/2/11
ok i will wait for my answer.. . .

# 887 :: 5/29/11
1. Too much cholesterol in the blood increases the risk of heart disease. Young women are generally less afflicted by high cholesterol than other grou. . .

# 888 :: 5/29/11
1. Too much cholesterol in the blood increases the risk of heart disease. Young women are generally less afflicted by high cholesterol than other grou. . .

# 889 :: 5/29/11
2. The figure below is a Normal quantile plot of the emissions of carbon dioxide (CO2) per person in 48 countries. The data set can be found under Ass. . .

# 890 :: 6/14/11
Question 890 has been Answered
I've a set of related questions on power analysis. Suppose I have an experiment with 5 groups and 5 DVs and intend to conduct MANOVA to determine . . .

MANOVA, Power

# 891 :: 6/25/11
X, Y, and Z are independent normally distributed random variables. The following information is known about these three variables: E (X) =4, . . .

# 892 :: 7/11/11
42 people judged their emotional response to six typeface designs. There were 12 buttons to present the emotions visually (via animated characters). P. . .

# 893 :: 7/12/11
Question 893 has been Answered
Elbow to fingertip length of men 99% confidence n=32, x- 14.50,s= 0.70 what is the margin of error. . .

Margin of Error, Confidence Intervals

# 894 :: 7/17/11
Question 894 has been Answered
Can percentages be converted to z score?. . .

Z-Score

# 895 :: 7/19/11
Question 895 has been Answered
In a sample of n = 36 selected from a population, where X = 96 and S = 12, what is the value of tSTAT if you are testing the null hypothesis H0: = 1. . .

1-sample t-test, test statistic

# 896 :: 7/26/11
Question 896 has been Answered
1. Given the following probability distributions: Group A X P(X) 2 0.15 4 0.20 6 0.25 8 0.15 10 0.25 a. Compute the expected v. . .

Expected Value

# 897 :: 7/27/11
Question 897 has been Answered
What is the probability for the following values of Z? a. Z < 1.35 b. Z > -1.84 and Z < 2.52 c. Z < 1.02 and Z > 2.77. . .

Area between, Z-Score

# 898 :: 8/1/11
Question 898 has been Answered
Hi, I believe this question may require a few back n forth emails from us as I'm not sure if I will cover everything that is required for you to an. . .

# 899 :: 9/5/11
Question 899 has been Answered
In a study , the average age of the male candidates who were affected , was 38.20 whereas the average age of the female subjects was calculated to 34. . .

Variance, Standard Deviation

# 900 :: 9/28/11
Question 900 has been Answered
Suppose we want to design a new placebo-controlled trial to evaluate an experimental medication to increase lung capacity. The primary outcome is pea. . .

# 903 :: 10/16/11
Consider a random sample of 9 observations, from a Normal distribution, with sample average 25.0. a) Calculate a 95% confidence interval for the p. . .

# 904 :: 10/24/11
Use MINITAB to generate 1200 individual values from a Standard Normal distribution (mean = 0, std. dev = 1).. . .

# 905 :: 12/3/11
Question 905 has been Answered
create a 95% confidence interval for the value of the population mean using the following information: a sample mean of 55, a sample standard deviatio. . .

Confidence Intervals

# 906 :: 12/3/11
Question 906 has been Answered
You want to test the hypothesis that the mean age for teachers is equal to 50. If you take a sample of 64 observations and find a sample mean of 49, w. . .

1-sample t-test

# 907 :: 12/3/11
Question 907 has been Answered
Suppose that you have a sample mean of 49 and a standard deviation of 3, but now found those values from a sample of 20 observations. test the hypothe. . .

1-sample t-test

# 908 :: 12/3/11
Question 908 has been Answered
Create a 90% confidence interval for the value of the population mean using the following information: A sample mean of 65, a sample standard deviatio. . .

1-sample t-test

# 909 :: 12/3/11
Question 909 has been Answered
Find the critical statistic for: A two tailed test with 50 observations with alpha equal to .001.. . .

Critical Value, t statistic

# 910 :: 12/3/11
Question 910 has been Answered
Find the appropriate critical statistic for : A one tailed test in the positive direction with 15 observations with alpha equal to 0.001.. . .

Critical Value, test statistic

# 911 :: 12/3/11
Question 911 has been Answered
Find the critical statistic for a one tailed test in the negative direction with 25 observations and alpha equal 0.01.. . .

Critical Value, t-statistic

# 912 :: 12/3/11
Question 912 has been Answered
Find the appropriate critical statistic for a two tailed test with 20 observations and alpha equal to 0.05.. . .

Critical Value, t-statistic

# 913 :: 12/5/11
Question 913 has been Answered
The mean is 112 oz, and the standard deviation is 40 oz. Compute the probability that the mean from a sample of 49 will fall between 103 and 121 oz. . .

Z-Score, Area between, Standard Error of the Mean

# 914 :: 12/6/11
Question 914 has been Answered
create a 95% confidence interval for the value of the population mean, given that their are 64 observations and a sample mean of 49, with a sample sta. . .

1-sample t-test, Confidence Intervals

# 915 :: 12/6/11
Question 915 has been Answered
create a 95%confidence interval for the value of the population mean, given that their is a sample mean of 49 and a standard deviation of 3 but now fo. . .

1-sample t-test, Confidence Intervals

# 916 :: 1/9/12
what is the diffrence betweenqualitative data and nominnnal data?. . .

# 918 :: 1/12/12
what is mode?. . .

# 919 :: 1/12/12
income and daily expense.the two variable will consider as discrete or continuous?. . .

# 920 :: 1/13/12
Question 920 has been Answered
The average service time at CheesePlate Restaurant is 3.5 minutes with a standard deviation of .04 minutes. A new order system claims it can improve . . .

1-sample t-test

# 921 :: 1/23/12
Consider the finite population of size N = 3, measurements on the variable x: {2, 3, 4}: a. derive the population probability distribution for the . . .

# 922 :: 1/23/12
A random sample of measurements on two quantitative variables x and y is taken from a population. The data for the variables x and y are: {(x,. . .

# 923 :: 1/23/12
The average life span of American male professors is 75.6 years, but standard deviation is unknown. A random sample of n = 5 recently (last 10 ye. . .

# 924 :: 1/23/12
Given the sample dataset of size n = 5: {2, -4, 1, 1, 5x}. Note that x is a real number. Obtain the empirical influence function for the mean an. . .

# 925 :: 1/30/12
Question 925 has been Answered
3 section of a statistics class containing 28,32 and 35 students averaged 83,80 and 76 respectively on same final exam. what 's the combined populatio. . .

weighted mean

# 926 :: 1/30/12
Question 926 has been Answered
A survey of random sample of people leaving an amusement park showed an average expenditure number 10.30k for the evening, the average of expenditure . . .

weighted mean

# 927 :: 2/2/12
A company that manufactures computer chips wants to use a multiple regression model to study the effect that different variables have on y, the total . . .

# 928 :: 2/17/12
what will be the standard deviation and the varience in each of the following casses (i) 2x (ii)2+x (iii) 2x+4 if var(x)=25. . .

# 929 :: 2/18/12
The following observations are weights of 10 potatoes in grams. Calculate the percentage of potatoes with weights greater than 25 grams and the range . . .

# 930 :: 2/21/12
Consider the ibuprofen function I(t) = 210110tt. I is in mg of ibuprofen and t is in hours. 1. Use the FACTORING method to find the t. . .

# 931 :: 3/13/12
to find total and average of 3 subjects. . .

# 932 :: 3/13/12
ou measure the weights of a random sample of twenty-five male runners. The sample mean is 60 kilograms (kg). Suppose that the mean weights of male r. . .

# 933 :: 3/17/12
Determine whether the New York Yankees or the Philadelphia Phillies had a relatively better runs producing season. The Yankees scored 960 runs and pl. . .

# 934 :: 3/17/12
The data shown represent the scores on a national achievement test for a group of 10th grade students. Find the approximate percentile ranks of these. . .

# 935 :: 3/25/12
I have two samples populations and want answer the question as to whether the difference in the means of the two samples are statisticall significant. . .

# 936 :: 3/26/12
You are interested in evaluating a new treatment for heart disease. (a) Discribe the population of interest. (b) Describe how you might obtain a rando. . .

# 937 :: 3/30/12
frequency and relative frequency distribution. use 7 classes of width 1.30 starting point 1.15 sample 26.... How will u do this im so lost.... The dec. . .

# 938 :: 4/4/12
random sample of 100 pieces of wire and wants to see if the thickness of a batch of wire meets minimum specifications. Assume that the population mea. . .

# 939 :: 4/5/12
When using a t test for dependent means, show the steps involved in calculating the estimated population variance based on scores in this sample: Par. . .

# 940 :: 4/13/12
solution to managerian stastics question. suppose that a consultant for the supermarket counts the number of arrival per hour during a sample of 150 h. . .

# 941 :: 4/15/12
Problem 3: A group of college students were surveyed to learn how many times they had visited a dentist in the previous year. The probability distribu. . .

# 942 :: 4/19/12
Please kindly help me with this Cost Benefit Analysis Proposal for New Employee. Please provide work in detailed step by step instructions thank you v. . .

# 943 :: 4/27/12
Suppose the Total Sum of Squares for a design with k=6 treatments and n=36 total measurements (six per treatment) is equal to 500. In each of the foll. . .

# 944 :: 4/29/12
Question 944 has been Answered
Mr. price Home analyzed the value of purchase made on credit by a sample of 25 credit card customers. The simple mean was found to be R170.08 with a s. . .

Confidence Intervals

# 945 :: 4/29/12
Question 945 has been Answered
In a survey of 1000 electors, 20% were found to favour party "stats". 1. Construct a 95% C.I for the percentagew in favour of party "stats". 2. What. . .

Confidence Intervals, Sample Size

# 946 :: 4/29/12
Question 946 has been Answered
The management of a mine wishes to investigate the effect of a 4-day workweek on absenteeism. 2 random sample of size 40 were selected. Employees of G. . .

2-sample t-test

# 947 :: 4/29/12
Question 947 has been Answered
Workers in 2 different mine groups were asked what they considered to be the most important labour-management problem. In Group A, 200 out of a random. . .

2-proportion test

# 948 :: 4/29/12
Question 948 has been Answered
It is important for airlines to know the approximate total weight of the baggage carried on each airplane. An airline researcher believes that the mea. . .

1-sample Z-test

# 949 :: 4/29/12
Question 949 has been Answered
The desired percentage of silicon dioxide in a certain type of cement is 5. A random sample of 36 specimens gave a sample average percentage of 5.21 a. . .

1-sample t-test

# 950 :: 4/30/12
A sample of 10 electronic tubes produced by a company showed a mean lifetime of 1200 hours and a standard deviation of 100 hours. estimate the mean an. . .

# 951 :: 4/30/12
1. A research team conducted a study of soft- drink preferences among residents in a test market prior to an advertising campaign for a new cola produ. . .

# 952 :: 5/4/12
23 parents were given a family reading survey....They were asked if they liked to read? The mean stats came back 4.00 The median stats 5.00 The stan. . .

# 953 :: 5/4/12
23 parents asked It is fun to read with my child....stats = mean 4.61 median 5.00 standard deviation .499. . .

# 955 :: 5/9/12
During nine days in a festival, the highest sale of a shop was on sunday and was 9005 more than the average sale for other days. If the standard dev. . .

# 956 :: 5/15/12
In a population of 5000 students, a simple random sample of 50 students is selected in order to estimate the weighted average mark for the population.. . .

# 957 :: 5/23/12
a researcher reports a mean pulse rate of 80 for the ampled patients. the data also revealed a standard deviation of 10.5. what percent of patients pu. . .

# 958 :: 6/9/12
dsfdsf. . .

# 959 :: 6/9/12
I need to determine whether a marketing campaign to increase spending at a direct marketing retailer has resulted in incremental spend. For this campa. . .

# 960 :: 6/21/12
a random sample of 50 men, 40% said they preferred walking up stairs than taking the elevator. In a random sample of 40 women, 50% said they preferred. . .

# 961 :: 6/25/12
assume that an apptitude test are normally distributed. if the mean score in on 140 points and standard deviation is 25 points. find the cut off passi. . .

# 962 :: 8/28/12
1. was the target goal reached for reameasurement period 1 or 2? 2. provide a quantitative analysis that compares remeasurement 1 and 2 data to the b. . .

# 963 :: 10/31/12
In traditional marketing research surveys, are purchase intent questions measured on a 5 point scale (e.g. definitely would buy, probably would be, et. . .

# 964 :: 10/31/12
Designing a study Create an example of a research question in an imaginary quantitative NURSING study you might design. Identify the independent and. . .

# 965 :: 10/31/12
Go to the online library and find a recent (no older than 3 years) article reporting the results of a nursing or health research study in which a stat. . .

# 966 :: 11/9/12
During the 2000 season, the home team won 138 of the 240 regular season National Football League games. Is this strong evidence of a home field advant. . .

# 967 :: 11/17/12
The table below shows the weights (in pounds) of 6 randomly selected women in each of three different age groups. Use a 0.01 significance level to tes. . .

# 968 :: 11/18/12
a self proclaimed psychic was tested with 100 cards face downand asked to determine what symbol, out of 5 possible symbols the card hado n it. How man. . .

# 969 :: 11/22/12
In May 1998, the New York Times carried an article by Adam Bryant describing a research project to relate two rather diverse phenomena: the performanc. . .

# 970 :: 12/6/12
Suppose you wish to test the effect of a new medication (X) compared to Prozac on the well-being of depressed individuals, using a standardized "well-. . .

# 971 :: 12/7/12
1. A few years ago, the Food and Drug Administration issued a strong warning against Procter & Gambles Rely tampon. The study of toxic shock syndrome. . .

# 972 :: 12/15/12
In Eurelia there are three categories of bicycle license, with different fees for each. The table below is based on a random sample of 122 Eurelian b. . .

# 973 :: 1/12/13
write a short note on lorenz curve. . .

# 974 :: 1/19/13
1. A population of size 1,000,000 claims has mean cycle time of 15 days, and a standard deviation of 4. 100 random samples of each size 64 are selecte. . .

# 975 :: 2/13/13
is farm size a discrete or continuous data?. . .

# 976 :: 2/20/13
Can you give examples of Ratio,Nominal,Ordinal and Interval and how these terms relate to business. . .

# 977 :: 3/3/13
British airways employs you as cunsultant to analyse the departure time of flight leaving Cape Town International Airport. The acceptance time frame f. . .

# 978 :: 3/25/13
why we need to measure variability?. . .

# 979 :: 3/26/13
the average cost for service provided per person per day is random variable with normal distribution of N$ 100 and a standard deviation of N$ 22. Wha. . .

# 980 :: 3/27/13
1. Does dichotomizing the dependent variable (i.e. logistic regression) decrease power in relation to a continuous dependent variable? I noticed the l. . .

# 981 :: 3/27/13
For Question 980 you Submitted Question : 1. Does dichotomizing the dependent variable (i.e. logistic regression) decrease power in relation . . .

# 982 :: 3/27/13
My question has to do with power. Suppose in a clinical study you have two groups with 10 subjcects in each group. No significance at the .05 level is. . .

# 983 :: 4/11/13
find the standard deviation from the fallowing data. Wages-0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40. No. Of workers-2, 5, 7, 13, 21, 16, . . .

# 984 :: 4/16/13
a sample of 35 workers was randomly selected from a workforce of 110 to estimate the average amount spent weekly at a canteen by each worker.the sampl. . .

# 985 :: 4/16/13
Usablestats.com Team, I thought you might like to know some reasons why you are not getting enough Social Media and Organic search engine traffic f. . .

# 986 :: 5/6/13
general scores on academic performance in english language using 60 participant. let the highest score be 90 and 10. use a class inertval of 10 create. . .

# 987 :: 5/14/13
1000 students had written an examination the mean of test is 35and standed deviation is 5. Assuming the distribution to be normal find 1. how many. . .

# 988 :: 6/8/13
A drug company want to know if new drug lowest the cholesterol below the target level of 120.A random sample of 25 questions has a mean of 115 and a s. . .

# 989 :: 6/16/13
The Ministry of Environment, Science and Technology has one of its administrative centers located out of town and the majority of employees drive to w. . .

# 990 :: 6/22/13
Two impendent samples of signs 9 and 8 gave the sum of squares of deviation from their respective means as 160 and 91 can the samples be regarded as d. . .

# 991 :: 6/22/13
In an industry,200 workers,employed for a specific job,were classified according thier performance and training received/not received to test indepen. . .

# 992 :: 6/24/13
A test is given to graduates of tw buisness schools A and B. The scores are given out of 100. Test whether the school differ in quality by using Mann-. . .

# 993 :: 6/29/13
a bank manager recorded the number of hours taken to accomplish a particular task. He got the data below. Hours:10, 11, 12, 13, 14, 15, 16, 17, 18. Nu. . .

# 994 :: 7/2/13
4. Suppose that 100 people are given lipid lowering drugs and that the drug appears to be effective in about 20 of them. Effective is defined as lowe. . .

# 995 :: 7/3/13
I amusing 20 participants to study whether a new drug is more effective than the current drug in the treatment of schizophrenia before they mass produ. . .

# 996 :: 7/12/13
how do we calculate the confidence interval based on the population standard deviation. . .

# 997 :: 7/19/13
I am analyzing survey data from one university. Data set #1includes prenursing experience without a clinical experience in older adults. Data set #2. . .

# 998 :: 8/1/13
The mean of a normally distributed group of weekly incomes of a large group of executives is $910 and the standard deviation is $100. What is the z-sc. . .

# 999 :: 8/4/13
The mean serum cholesterol level of 25 men ages 65-74 is 231, with a sample standard deviation of 50. For 25 women of the same age, the mean serum ch. . .

# 1000 :: 8/21/13
Fire Insurance is a business based on risk. If the mean cost of a fire is = 300 per person and the standard deviation is σ = 400. . .

# 1001 :: 8/24/13
The following data gives gender and employment status of civilian labour force age 16 to 24 years as of March, 2006. Employed . . .

# 1002 :: 8/25/13
this is a test. . .

# 1003 :: 8/28/13
In a BMT class test the scores of 8 students are: 11; 10; 6; 3; 11; 10; 9; 11. Assume the sores are a simple random sample from a normally distributed. . .

# 1004 :: 8/29/13
three vehicles with a carrying capacity of 12 passengers each are used to ferry 30 international tourists and 5 local tourists from or tambo airport t. . .

# 1005 :: 9/16/13
Do creative people make better salespeople? Ten sales staff in a large company were given a creativity test (scores range from 0 to 20, with higher s. . .

# 1006 :: 9/16/13
Do creative people make better salespeople? Ten sales staff in a large company were given a creativity test (scores range from 0 to 20, with higher s. . .

# 1007 :: 9/16/13
Do creative people make better salespeople? Ten sales staff in a large company were given a creativity test (scores range from 0 to 20, with higher s. . .

# 1008 :: 9/16/13
Do creative people make better salespeople? Ten sales staff in a large company were given a creativity test (scores range from 0 to 20, with higher s. . .

# 1009 :: 9/19/13
the probability that husband and wife will b alive after 20 years from now is 0.8 and 0.9 respectively.find the probability that in 20 years time 1. b. . .

# 1010 :: 9/24/13
If the mean is 24 inches and the SD is 4.5 inches, What is the height of a plant with a z score of 0? My question is what is the formula used to sol. . .

# 1011 :: 9/26/13
median of (4,7,9,3,2)power1/4. . .

# 1012 :: 9/26/13
median of (4,7,9,3,2)power1/4. . .

# 1013 :: 9/27/13
A 12 ounce bottle of beer has 355 ml. The Random Brewing Company sets its machinery so that the contents of a bottle is normally distributed with a me. . .

# 1014 :: 9/27/13
Suppose that the number of customers who enter a supermarket each hour is normally distributed with a mean of 570 and a standard deviation of 170. The. . .

# 1015 :: 9/27/13
Suppose that the number of customers who enter a supermarket each hour is normally distributed with a mean of 570 and a standard deviation of 170. The. . .

# 1016 :: 9/27/13
The advertising firm of McMann and Tate has put out bids for two separate contracts. Based on past experience, they believe that they have a 0.7 proba. . .

# 1017 :: 9/27/13
To examine the effectiveness of its four annual advertising promotions, a mail order company has sent a questionnaire to each of its customers, asking. . .

# 1018 :: 9/29/13
detailed description of -the mean deviation about for the numbers 4/11, 6/11, 8/11, 9/11, 12/11. 8/11 is and 2nd question is the mean and SD for a,b . . .

# 1019 :: 10/3/13
Professor gill selects 20 digits from the table and even digit tells her to use a true statement and odd tells her to use a false statement.. Using a . . .

# 1020 :: 10/13/13
The applicants require to take the university examination for admission in engineering collage. Scores on the university are roughly normally distrib. . .

# 1021 :: 10/13/13
In studying the behavior of air support roofs, the random variables X, the inside barometric pressure (in inches of mercury) and Y, the outside barome. . .

# 1022 :: 10/13/13
State the different type of probability distribution of the continuous random variable. . .

# 1023 :: 10/18/13
The mean and standard deviation for the quality point averages of a random sample of 36 college seniors are calculated to be 2.6 and 0.3, respectively. . .

# 1024 :: 10/22/13
Although cities encourage carpooling to reduce traffic congestion, most vehicles carry only one person. For example, nationally 75.5% of the people dr. . .

# 1025 :: 10/22/13
Although cities encourage carpooling to reduce traffic congestion, most vehicles carry only one person. For example, nationally 75.5% of the people dr. . .

# 1026 :: 10/23/13
the standard deviation of the average scores on the SAT with mean 501 and standard deviation 112 and SRS of 100 students. . .

# 1027 :: 10/24/13
if you have more than one situation(variance) occurring in the same case do you multiply the success rates for each or average them to get the final . . .

# 1028 :: 10/26/13
Some national statistics indicate the self-reported number of minutes per week of exercise is μ = 96.8 among college students. At the University . . .

# 1029 :: 10/30/13
Find the z-scores that bound the middle 15% of the standard normal distribution. (Give your answers correct to two decimal places.). . .

# 1030 :: 11/5/13
the length of country and western songs is normally distributed and has a mean of of 170 seconds with a standard deviation of 49 seconds. find the pro. . .

# 1031 :: 11/5/13
the length of country and western songs is normally distributed and has a mean of of 170 seconds with a standard deviation of 49 seconds. find the pro. . .

# 1032 :: 11/18/13
Assume that a random sample is used to est. a population proportion p. find margin of error E that corresponds to the given statistics and confidence . . .

# 1033 :: 11/20/13
IQ test was administered to 5 person before and after they are trained. The result are given below: Candidates: I II III IV V IQ before train. . .

# 1034 :: 11/22/13
The heights of 20- to 29-year-old females are known to have a population standard deviation 1) �� = 2.7 inches. A simple random sample . . .

# 1035 :: 11/23/13
IQ test was administered to 5 person before and after they are trained. The result are given below: 10 Candidates: I II III IV V IQ before training. . .

# 1036 :: 11/23/13
IQ test was administered to 5 person before and after they are trained. The result are given below: 10 Candidates: I II III IV V IQ before training. . .

# 1037 :: 11/28/13
A random sample will be selected from the adult residents of a particular city, the sample proportion will be used to estimate p, the proportion of al. . .

# 1038 :: 11/28/13
A manufacturer of small appliances purchases coffeepot handles from an outside vendor. If a handle is cracked, it is considered defective and can't be. . .

# 1039 :: 11/30/13
"Holding all other elements equal, an increase in sample size will result in a wider confidence interval." I want to understand why this is true, I th. . .

# 1040 :: 12/3/13
50 machine 5000kg cotton 8 hours 25 machine x cotton 12 hours. . .

# 1041 :: 12/4/13
Let x̄1 represent the mean of a random sample of size n1, selected from the population x 2 3 7 F(x) 1/3 1/3 1/3 and x̄2 represent the m. . .

# 1042 :: 12/4/13
If a random sample is to be drawn from a population consisting of 5000 sampling units with a variance of 20% and a desired standard error of 1.6%. Wha. . .

# 1043 :: 12/4/13
A college is considering making the purchase of a laptop computer a requirement for some of its programs. In the past, only 20% of students. . .

# 1044 :: 12/13/13
The Boss is a small Italian restaurant with 6 waiters and waitresses. The average service time at the restaurant for a table (of any size) in 80 minut. . .

# 1045 :: 12/15/13
how can i find the mean of the remaining observation if the mean of 30 observation is 5 and one of the value is 34?. . .

# 1046 :: 12/16/13
You are conducting a study on what socio-demographic factors could be behind the behavioral problems of students. You are looking at how many times a. . .

# 1047 :: 12/17/13
Which is the best approximation of the value of 730 − − − √ 3 ?. . .

# 1048 :: 12/24/13
A researchers wish to estimate, with 95% confidence, the proportion of people who own a home computer. A previous study shows the 40% of those intervi. . .

# 1049 :: 12/24/13
The same researcher wishes to estimate the proportion of executives who own a car phone. She wants to be 90% confident and be accurate within 5% of th. . .

# 1050 :: 12/24/13
Suppose a sample of farmers is to be selected for estimating the cost of cultivation of maize per hectare. The precision is to be within 20 bi. . .