Question 3 (10 points) Percent body fat. The dataset Jacksonsav includes data from the Jackson study, a study of 655 persons who had several physical measures recorded, such as height, weight, body mass index, together with demographic characteristics. The relevant variables in the le for this problem are as follows: sex = 1 for men, 0 for women; pctfat = percent of body fat. a. b. Produce the boxplots of percent body fat by sex. What does this graphic suggest? Compare statistically the mean percent body fat between men and women, using the independent samples t-test in SPSS (assume equal variances for the two groups). Compute the 95% condence interval for the mean difference in percent body fat between the two groups, using SPSS. Discuss your ndings. . Conrm the SPSS independent samples t-test results using a hand calculation of the equal variances t-test. Conrm the SPSS 95% condence interval using hand calculations