(6.4)8c

The waiting times (in minutes) of a random sample of

20

people at a bank have a sample standard deviation of

4.6

minutes. Construct a confidence interval for the population variance

2

and the population standard deviation

.

Use a

95%

level of confidence. Assume the sample is from a normally distributed population.

Question content area bottom

Part 1

What is the confidence interval for the population variance

2?

(12.212.2,45.145.1)

(Round to one decimal place as needed.)

Part 2

Interpret the results. Select the correct choice below and fill in the answer box(es) to finish your choice.

(Round to one decimal place as needed.)

A.

With

95%

confidence, you can say that the population variance is between

12.212.2

and

45.145.1.

Your answer is correct.

B.

With

5%

confidence, you can say that the population variance is between

enter your response here

and

enter your response here.

C.

With

5%

confidence, you can say that the population variance is

greater

than

enter your response here.

D.

With

95%

confidence, you can say that the population variance is

less

than

enter your response here.

Part 3

What is the confidence interval for the population standard deviation

?

(enter your response here,enter your response here)

(Round to one decimal place as needed.)