A statistician wants to test for the equality of means in two independent samples drawn from normal populations of people enrolled in a diet program. The number of pound lost at the completion of the program data follow:
Sample 1 7 9 6 15 7 10 8 12
Sample 2 2 25 9 15 10 18 5 22 27 3
a. Can the statistician conclude at the 5% signi cance level that there is no di erence between the two population means?
b. Estimate with 95% con dence the ratio of the two population variances.