| No. & Date Asked | Question |
# 2 :: 10/23/07
 |
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
|
What is the critical z score for a one tailed test with alpha = .01.. . .
Alpha,
Z-Score |
# 4 :: 10/23/07
|
Where can I find a Z score chart ?. . .
Z-Score |
# 5 :: 10/23/07
|
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
|
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
|
How do you make data normally distributed?. . .
Transformation,
Log Transformation,
Monte-Carlo,
Bootstrap,
Non-Normal Data,
Normal Distribution,
Non-Parametric |
# 10 :: 10/23/07
|
What is the difference between a Z-Scores and Process Sigma?. . .
Process Sigma,
Z-Score,
1.5 Sigma Shift |
# 11 :: 10/23/07
|
What is the z value for 1.648?. . .
Z-Score |
# 12 :: 10/23/07
|
Can a z score be calculated by input of a proportion only?. . .
Proportion,
Z-Score |
# 13 :: 10/23/07
|
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
|
What percent of the time should this occur? (Z-Score) ?. . .
Z-Score,
Normally Distributed,
Standard Deviation,
Normal Curve |
# 15 :: 10/23/07
|
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
|
What is the Trimmed Mean For?. . .
Trimmed Mean,
Task Time |
# 17 :: 10/29/07
|
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
|
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
|
How do you calculate standard deviation?. . .
Standard Deviation |
# 22 :: 10/29/07
|
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
|
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
|
What does a Z-score look like on a graph?. . .
Z-Score |
# 26 :: 10/29/07
|
How do you calculate z-scores from batting averages?. . .
Z-Score |
# 27 :: 10/29/07
|
What does percentile rank mean?. . .
Percentile,
Percentile Rank |
# 28 :: 10/29/07
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
What is the basic formula for the z-score other than table of areas?. . .
Newton-Raphson,
Z-Score |
# 40 :: 10/29/07
|
What are the properties of the z-score in data analysis?. . . |
# 41 :: 10/29/07
|
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
|
What are the units of z-score?. . .
Z-Score,
Units of Measure |
# 43 :: 10/29/07
|
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
|
How do you standardize data?. . .
Standardize |
# 46 :: 10/29/07
|
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
|
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
|
How do you calculate T scores?. . . |
# 50 :: 10/29/07
|
What is the DPMO calculation for a discrete task?. . . |
# 51 :: 10/29/07
|
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
|
In order to calculate dpmo, why do you need multiply 1 million?. . .
DPMO |
# 58 :: 10/29/07
|
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
|
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
|
If a standard deviation of a set of data is zero, what can you conclude about the set of values?. . . |
# 66 :: 11/6/07
|
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
|
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
|
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
|
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
|
How do you use the spss table?. . . |
# 77 :: 1/22/08
|
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
|
What does measuring the standard deviation of a set of data tell you about the data. . . |
# 79 :: 2/4/08
|
How do you figure the individual X value of interest. . . |
# 80 :: 2/4/08
|
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
|
calculate the z score of 9o th percentile?. . . |
# 82 :: 2/14/08
|
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
|
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
|
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
|
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
|
Where is using the t statistic an appropriate alternative to using a z-score?. . . |
# 90 :: 2/23/08
|
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
|
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
|
Which has the tighter spec limits, 3 sigma or 6 sigma?. . . |
# 93 :: 2/29/08
|
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
|
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
|
The mean is ì = 60.0 and the standard deviation is ó = 4.0.
Find the probability that X is less than 53.0.. . .
Z-Score |
# 97 :: 3/1/08
|
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
|
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
|
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
|
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
|
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
|
What constitutes a small sample size in a test of two populations? . . .
t-distribution,
Z-Statistic,
Small Sample |
# 125 :: 3/20/08
|
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
|
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
|
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
|
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
|
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
|
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
|
Prediction of business failure using statistical methods. . . |
# 141 :: 4/7/08
|
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
|
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
|
Will the t statistics calculated from 4 observations valid?. . .
t-statistic,
t-distribution,
Small Sample |
# 146 :: 4/9/08
|
what is the z-score that corresponds to the 20th percentile of the normal distribution. . .
Z-Score,
Percentile |
# 147 :: 4/12/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
When calculating confidence interval estimates...how is the x and standard deviation calculated?. . .
Standard Deviation,
Confidence Intervals |
# 164 :: 4/23/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
Find the probability that a randomly selected adult has an IQ that is less than 130. . .
IQ Score,
Z-Score |
# 180 :: 5/5/08
|
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
|
What is the difference between a population standard deviation and a sample standard deviation?. . .
Standard Deviation,
Degrees of Freedom |
# 182 :: 5/5/08
|
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
|
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
|
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
|
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
|
How do I do a Chi-Square test on unequal sample sizes?. . .
Chi-Square,
Unequal Sample Size |
# 189 :: 5/12/08
|
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
|
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
|
When would you use regression correlation at your place of employment, in your education, or in politics?. . . |
# 193 :: 5/14/08
|
How can I determine the sample size for data that is discrete but not binary?. . . |
# 194 :: 5/14/08
|
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
|
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
|
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
|
Find the value of Z a/2 that corresponds to a level of confidence of 98.22 percent.. . . |
# 199 :: 5/19/08
|
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
|
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
|
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
|
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
|
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
|
What does a z value mean?. . .
Z-Score,
Z-value,
Standard Score |
# 205 :: 5/22/08
|
Find the number z that has cumulative proportion 0.8. . .
Z-Score |
# 206 :: 5/24/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
A z score of 1.04 shows a percentage value of?. . .
Z-Score |
# 222 :: 6/7/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
Between what two values of Z will 88% of the middle data values fall between?. . .
Z-Score |
# 234 :: 6/13/08
|
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
|
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
|
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
|
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 ó = 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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
Which type of data set can the mean not be calculated?. . .
skew,
mean,
Geometric Mean,
Median |
# 272 :: 7/10/08
|
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
|
The lowest 25% of the normal distribution falls below what z-score and t-score. . .
T score,
Z-Score |
# 276 :: 7/11/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
How can you use a Z score to interpret data in a school. . .
Z-Score |
# 294 :: 7/28/08
|
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
|
How can I calculate a Z score with only the mean and the standard deviation?. . .
Z-Score |
# 296 :: 7/28/08
|
What is the Z value that corresponds to a probability of .05?. . . |
# 297 :: 7/28/08
|
What is the formula for finding the t-statistic. . .
Newton-Raphson,
t-statistic |
# 298 :: 7/29/08
|
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
|
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
|
What is the advantage of a t-score over a z-score?. . .
t-statistic,
t-score |
# 303 :: 8/1/08
|
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
|
Is a number whose z score is equal to zero equal to the mean?. . . |
# 305 :: 8/2/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
Can the bell curve probability value be over the value of 1?. . .
Normal Curve,
Bell Curve |
# 318 :: 8/6/08
|
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
|
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
|
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
|
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
|
What effect does an increase in the level of confidence have on the width of the confidence interval?. . .
Confidence Level |
# 325 :: 8/7/08
|
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
|
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
|
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
|
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
|
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
|
When we reject the null hypothesis, we are certain that the null hypothesis is false ?. . .
Null Hypothesis |
# 332 :: 8/10/08
|
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
|
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
|
find the z value so that 20% of the standard normal curve lies to the right of Z. . .
Z-Score |
# 335 :: 8/10/08
|
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
|
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
|
is the chi-square distribution used for inferences about the population mean when the standard deviation is unknown?. . .
Chi-Square |
# 338 :: 8/11/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
Why is population shape of concern when estimating a mean?. . . |
# 347 :: 8/14/08
|
Why is population shape of concern when estimating a mean? What does sample size have to do with it?. . . |
# 348 :: 8/15/08
|
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
|
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
|
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
|
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
|
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
|
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
|
If Range = (6 * Standard Deviation), can it be concluded that Data is normal. . .
Nomal Distribution,
Probability Plot |
# 356 :: 8/24/08
|
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
|
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
|
In the same set of data,can two or more elements have the same z score.. . .
Z-Score |
# 359 :: 8/27/08
|
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
|
What does a negative z-score represent? eg. -0.381. . . |
# 361 :: 8/30/08
|
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
|
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
|
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
 |
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
|
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
|
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
|
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
|
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
|
Can you give me a formula to calculate sample size?. . .
Sample Size,
Margin of Error |
# 372 :: 9/8/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
How do you dertermine a z-score for continuous data?. . .
Z-Score |
# 390 :: 9/18/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
What is the height of a man with the z score of -1.7?. . .
Z-Score |
# 410 :: 9/24/08
|
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
|
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
|
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
|
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
|
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
|
how do i find the lower 25% and upper 75% and the interquartile range. . .
Interquartile Range |
# 416 :: 9/27/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
why does a z score always have a mean of 0 and a standard deviation of 1?. . .
Standard Normal Curve |
# 453 :: 10/4/08
|
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
|
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
|
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
|
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
|
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
|
20% kids danced. If 10 were selected at random, find probability that exactly four danced.. . .
BINOMDIST,
Binomial pmf |
# 461 :: 10/6/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
Does normal distribution is something to do with Altman Z-Score?. . .
Altman Z-Score,
Z-Score |
# 481 :: 10/20/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
if an eligible couple on an average has 3.3 children then the birth rate will be?. . . |
# 493 :: 11/4/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
(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
|
In the following regression, X = weekly pay, Y = income tax withheld, and n = 35 McDonald’s employees. (a) Write the fitted regression equation. (b) S. . .
Regression Analysis,
Slope |
# 546 :: 12/10/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
Why does the main factor MSs in 2 way ANOVA sometimes carry along interaction effect?. . .
ANOVA,
2-Way ANOVA |
# 563 :: 12/19/08
|
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
|
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
|
The coefficient of correlation between two variables X and Y was computed to be ƒ{0.60. This means
a. the coefficient of determination is 0.
b. a. . .
Correlation,
coefficient of determination |
# 566 :: 12/19/08
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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 team’s 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
|
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
|
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
|
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
|
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
|
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
|
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
|
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
|
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 |
