Question 1

A sample of 16 students showed that the variance in the number of hours they spend studying is 25. At 95% confidence, test to see if the variance of the population is significantly different from 30. Use the critical value approach.

Accepted Answer

The answer of A sample of 16 students showed that...

Question 2

We are interested in determining whether or not the variances of the starting salaries of accounting majors is significantly different from management majors. The following information was gathered from two samples.  At 90% confidence, test to determine whether or not the variances are equal.

Accepted Answer

The answer of We are interested in determining whether or...

Question 3

A company claims that the standard deviation in their delivery time is less than 5 days. A sample of 27 past customers is taken. The average delivery time in the sample was 14 days with a standard deviation of 4.5 days. At 95% confidence, test the company's claim. Use the critical value approach.

Accepted Answer

The answer of A company claims that the standard deviation...

Question 4

The average grade of a sample of 30 students on their second statistics examination was 85 with a standard deviation of 11. Is the variance of the population significantly more than 80? Use a 0.05 level of significance.

Accepted Answer

The answer of The average grade of a sample of...

Question 5

ACT scores of a sample of UTC students are shown below.  
a.Compute the mean and the variance.
b.At 95% confidence, test to determine whether or not the variance of the ACT scores of the population of UTC students is significantly more than 8.

Accepted Answer

The answer of ACT scores of a sample of UTC...

Question 6

Do the following data indicate that the variance of the population from which this sample has been drawn is significantly more than 17? Use $\alpha$ = 0.05.

Accepted Answer

The answer of Do the following data indicate that the...

Question 7

A sample of 22 bottles of soft drink showed a variance of 0.64 in their contents. At 95% confidence, determine whether or not the standard deviation of the population is significantly different from 0.7. Use the critical value approach.

Accepted Answer

The answer of A sample of 22 bottles of soft...

Question 8

A large company has claimed that the standard deviation of the monthly incomes of their employees is less than or equal to $120. To test their claim, a random sample of 76 employees of the company was taken; and it was determined that the standard deviation of their incomes was $135. At 90% confidence, test the company's claim.

Accepted Answer

The answer of A large company has claimed that the...

Question 9

We are interested in determining whether or not the variances of the sales at two small grocery stores are equal. A sample of 21 days of sales at Store A and a sample of 16 days of sales at Store B indicated the following.  
a.Provide the hypotheses to be tested.
b.Compute the test statistic.
c.Determine the critical value of F at 95% confidence.
d.Compute the p-value and use it to test the above hypotheses.

Accepted Answer

The answer of We are interested in determining whether or...

Question 10

A random sample of 20 observations showed a standard deviation of 8. At 95% confidence, test to see if the variance of the population is significantly less than 65. Use the critical value approach.

Accepted Answer

The answer of A random sample of 20 observations showed...

Quiz 11: Inferences About Population Variances

A sample of 16 students showed that the variance in the number of hours they spend studying is 25. At 95% confidence, test to see if the variance of the population is significantly different from 30. Use the critical value approach.

We are interested in determining whether or not the variances of the starting salaries of accounting majors is significantly different from management majors. The following information was gathered from two samples. At 90% confidence, test to determine whether or not the variances are equal.

A company claims that the standard deviation in their delivery time is less than 5 days. A sample of 27 past customers is taken. The average delivery time in the sample was 14 days with a standard deviation of 4.5 days. At 95% confidence, test the company's claim. Use the critical value approach.

The average grade of a sample of 30 students on their second statistics examination was 85 with a standard deviation of 11. Is the variance of the population significantly more than 80? Use a 0.05 level of significance.

ACT scores of a sample of UTC students are shown below. a.Compute the mean and the variance. b.At 95% confidence, test to determine whether or not the variance of the ACT scores of the population of UTC students is significantly more than 8.

Do the following data indicate that the variance of the population from which this sample has been drawn is significantly more than 17? Use α\alphaα = 0.05.

A sample of 22 bottles of soft drink showed a variance of 0.64 in their contents. At 95% confidence, determine whether or not the standard deviation of the population is significantly different from 0.7. Use the critical value approach.

A random sample of 20 observations showed a standard deviation of 8. At 95% confidence, test to see if the variance of the population is significantly less than 65. Use the critical value approach.