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No. & Date AskedQuestion
# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

# 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

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

Standard Deviation

# 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

# 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