8. (7 points) Suppose in question 7, we would like to incorporate another variable such as the number of courses taken by students into the model in order to make an accurate prediction of the GPA. a) [2] Write the least squares prediction equation for the GPA using the final score and number of courses. Student's name: Please go on to the next page. .. Statistics STAT 106 Page 7 of 7 b) [5] Conduct the global F -test of model usefulness at the a = .05 level of significance write down your conclusion