Suppose that you would like to use a multiple regression model to predict salary (Yi) based on three explanatory variables: number of years of education (X1,i), gender (X2,i) and number of prior years of employment (X3,i). Suppose further that X2,i is an indicator variable that only takes two values: X2,i is 1 if the ith person is female, otherwise X2,i is 0.

Suppose that you are interested in testing the null hypothesis that there is no difference in the salaries of males and females against the alternative hypothesis that there is a difference. Can you devise an appropriate test statistic that would be useful in testing this hypothesis?