Data Set 1 in Appendix B includes 40 pulse rates of men, and those pulse rates have a mean of 67.3 beats per minute and a standard deviation of 10.3 beats per minute. That data set also includes 40 pulse rates of women, and those pulse rates have a mean of 77.5 beats per minute and a standard deviation of 11.6 beats per minute.

a. Construct a 99% confidence interval estimate of the standard deviation of the pulse rates of men.

b. Construct a 99% confidence interval estimate of the standard deviation of the pulse rates of women.

c. Compare the variation of the pulse rates of men and women. Does there appear to be a difference?

Assume that each sample is a simple random sample obtained from a population with a normal distribution.