Exercise 7.1 showed a multiple regression model predicting RFFT score from statin use and age. For this problem, an interaction term is added between statin use and age.

(a) Write the model equation.

(b) Interpret the model coefficients.

(c) Is there statistically significant evidence that the association between RFFT score and age differs by whether someone is a statin user? Explain your answer.
Data From Exercise 7.1

Estimate Std. Error t value Pr(>|t|) (Intercept) 140.2031 5.6209 24.94 0.0000 Statin -13.9720 15.0113 -0.93 0.3524 Age Statin:Age -1.3149 0.1040 -12.65 0.0000 0.2474 0.2468 1.00 0.3166