From the data on CAT scans in Exercise 8-45

(a) Find a two-sided 95% confidence interval for the standard deviation.

(b) What should you do to address any reservations about the confidence interval you found in part (a)?

Exercise-45

A healthcare provider monitors the number of CAT scans performed each month in each of its clinics. The most recent year of data for a particular clinic follows (the reported variable is the number of CAT scans each month expressed as the number of CAT scans per thousand members of the health plan): 2.31, 2.09, 2.36, 1.95, 1.98, 2.25, 2.16, 2.07, 1.88, 1.94, 1.97, 2.02.