In a random sample of 50 refrigerators, the mean repair cost was

$146.00

and the population standard deviation is $17.80

.

Construct a 90% confidence interval for the population mean repair cost. Interpret the results.

Construct a 90% confidence interval for the population mean repair cost.

The 90% confidence interval is ( ? , ? )

(Round to two decimal places as needed.)

I

nterpret you results. Choose the correct answer below.

A.With 90% confidence, it can be said that the confidence interval contains the true mean repair cost.

B.With 90% confidence, it can be said that the confidence interval contains the sample mean repair cost.

C.The confidence interval contains 90% of the mean repair costs.