2. Q2. (5 marks) Suppose we have a data set with ve predictors: 0 X1 =GPA ' X2 =10 . X3 =Gender(0=female, 1=male) . X4 =Interaction between GPA and IQ . X5 =Interaction between GPA and Gender. The reSpOnse variable, Y, is starting salary after graduation (in thousands of dollars). Suppose we get the following regression coefcient estimates: 80:5, 1=8, 62:02, 63:10, 54:0.05, 55:2 a. (1 mark) Write down the estimated model equation in terms of 17',X1, X2 and X3. b. (3 marks) Which one of the following statements is correct and why? Show any working you do. i. For a xed value of IQ and GPA, males earn more on average than females provided that the GPA is high enough. ii. For a xed value of IQ and GPA, females earn more on average than males. iii. The difference in expected salary between males and females increases as GPA increases. iv. An increase in ID by one point is associated with a reduction in expected salary, provided GPA is high enough. 0. (1 mark) True or False: Since the coefcient for the GPA:IQ interaction term is very small, there is very little evidence of an interaction effect. Justify your