The Manager of the Service Department of a Local Car

Multiple Choice

The manager of the service department of a local car dealership has noted that the service times of a sample of 15 new automobiles has a standard deviation of 4 minutes. A 95% confidence interval estimate for the variance of service times for all its new automobiles is _____.

A) 8.58 to 39.79
B) 4 to 16
C) 4 to 15
D) 1.64 to 1.96