In Problem 12.4 on page 423, the percentage of alcohol was used to predict wine quality (stored in VinhoVerde). For those data, SSR = 21.8677 and SST = 64.0000.
a. Determine the coefficient of determination, r2, and interpret its meaning.
b. Determine the standard error of the estimate.
c. How useful do you think this regression model is for predicting sales?