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 47 businessdays, the mean closing price of a certain stock was $117.92. Assume the population standard deviation is $10.10.

The90% confidence interval is ? (Round to two decimal places asneeded.)

The95% confidence interval is? (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 price of the stock is outside the bounds of the90% confidenceinterval, and95% confident for the95% interval.

B.

You can be certain that the closing price of the stock was within the90% confidence interval for approximately 42 of the 47 days, and was within the95% confidence interval for approximately 45 of the 47 days.

C.

You can be certain that the population mean price of the stock 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 price of the stock is between the bounds of the90% confidenceinterval, and95% confident for the95% interval.