5. A health spa claims that a new exercise program will reduce a person's waist size at

least 2 centimeters on average over a 5-day period. The waist sizes, in centimeters, of

six men who participated in this exercise program are recorded before and after the

5-day period in the following table:

By computing a 96% confidence interval for the mean reduction in waist size, determine

whether the health spa's claim is valid. Assume the distribution of differences in waist

sizes before and after the program to be approximately normal.