In a multiple regression model using 310 students to explain college grade point average, the following explanatory variables are...

In a multiple regression model using 310 students to explain college grade point average, the following explanatory variables are initially included in the regression: high school GPA, ACT score, number of credits completed, mother’s years of education, and father’s years of education. The R-squared is .436. When the two parents’ education variables are dropped, the R-squared becomes .381. Are the parents’ education variables significant at the 5% level? (Hint: remember that the lectures and the book both explain how to conduct an F-test of joint significance using R-squared values from two regressions).