Does college grade point average (GPA) depend on gender? Does it depend on class (freshman, sophomore, junior, senior)? In a study, the following GPA data were obtained for random samples of college students in each of the cells.

(a) List the factors and the number of levels of each factor.

(b) Use two-way ANOVA and the following Minitab printout to determine if there is any evidence of interaction between the two factors at a level of signifi­cance of 0.05.

(c) If there is no evidence of interaction, use two-way ANOVA and the Minitab printout to determine if there is a difference in mean GPA based on class. Use a 5 0.05.

(d) If there is no evidence of interaction, use two-way ANOVA and the Minitab printout to determine if there is a difference in mean GPA based on gender. Use a 5 0.05.

Class Gender Freshman Sophomore Senior Junior Male 2E8 2.1 2.93 1.1 Female 2E1 2.9 2.6 2.42.6 E8.3 Minitab Printout of GPA Based on Gender and class Analysis of Variance for GPA Source Gender Class Interaction Error Total DF 0.281 2.226 0.286 5.365 8.159 MS 0.281 0.742 0.095 0.224 1.26 3.32 0.43 0.273 0.037 0.736 24 31