The Manager of a Video Library Would Like the Variance

Multiple Choice

The manager of a video library would like the variance of the waiting times of the customers not to exceed 2.30 minutes-squared. He would like to add an additional billing counter if the variance exceeds the cut-off. He checks the recent sample data. For a random sample of 24 customer waiting times, he arrives at a sample variance of 3.8 minutes-squared. The manager assumes the waiting times to be normally distributed. At α = 0.05, which of the following is the critical value ?

A) 13.091
B) 32.007
C) 35.172
D) 38.076