(2) We would like to do an F test of goodness of fit for the whole equation. Please demonstrate your answer: (Note: at a 5% significance level, the critical value of the F statistic is: F(4,180) = 2.42, F(4,181) = 2.43, and F(5,180) = 2.26)
(3) How to test whether there is gender differentiation in the impact of earnings and age on contribution at the same time? Specifically, (i) Please write out the new model you would like to estimate. (ii) Please write out the null hypothesis. (iii) Please write out the test statistic (Hint: The goal of this question is to examine the interactive term and F test relating to groups of explanatory variables)