In a random sample of 40 refrigerators, the mean repair cost was $121.00 and the population standard deviation is $15.80. 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__,___?
Interpret you results. Choose the correct answer below.
A.The confidence interval contains 90% of the mean repair costs.
B.With 90% confidence, it can be said that the confidence interval contains the sample mean repair cost.
C.With 90% confidence, it can be said that the confidence interval contains the true mean repair cost.