2. The mathematics department at a university is interested in learning more about the grades that students earn in an introductory calculus class. A sample of n = 80 students who have taken this introductory calculus course during any semester of the three last three academic years is selected. The academic record for each selected student is reviewed. The professors in the math department determine that, of the available information for all students, the relevant variables are their nal grade in the calculus course, their high school percentile rank, their score on the algebra placement test given to all incoming students who plan to take a calculus course, their ACT Math score, and their ACT Natural Sciences score. C. One of the professors suggests testing whether adding the two ACT scores to the regression model would improve the model. The ANOVA table below shows the relevant values for the model containing all four explanatory variables. Conduct the appropriate F test to determine if adding the ACT scores improves the model. SS df MS F pvalue Regression 2986.2 4 746.5 7.6 3.5e'5 Residuals 7346.0 75 97.9 Total 10332.2 79