You are given the sample mean and the population standard deviation. Use this information to construct the90% and95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals.

From a random sample of 71 dates, the mean record high daily temperature in a certain city has a mean of 86.05F. Assume the population standard deviation is 15.14F.

The90% confidence interval is (

nothing

,

nothing

).

(Round to two decimal places asneeded.)

The95% confidence interval is (

nothing

,

nothing

).

(Round to two decimal places asneeded.)

Which interval iswider? Choose the correct answer below.

The95% confidence interval

The90% confidence interval

Interpret the results.

A.

You can be90% confident that the population mean record high temperature is outside the bounds of the90% confidenceinterval, and95% confident for the95% interval.

B.

You can be certain that the mean record high temperature was within the90% confidence interval for approximately 64 of the 71 days, and was within the95% confidence interval for approximately 67 of the 71 days.

C.

You can be certain that the population mean record high temperature is either between the lower bounds of the90% and95% confidence intervals or the upper bounds of the90% and95% confidence intervals.

D.

You can be90% confident that the population mean record high temperature is between the bounds of the90% confidenceinterval, and95% confident for the95% interval.