8.46 Independent random samples of size n = n 100 were selected from each of two populations. The mean and standard deviations for the two samples were x=125.2, x = 123.7, s = 5.6, and $2 = 6.8.

a. Construct a 99% confidence interval for estimating the difference in the two population means.

b. Does the confidence interval in part a provide suffi- cient evidence to conclude that there is a difference in the two population means? Explain.