Using the data of Problem 15.4 on page 581, stored in DomesticBerr, perform a natural logarithmic transformation of the dependent variable (calories). Using the transformed dependent variable and the percentage of alcohol and the number of carbohydrates as the independent variables, perform a multiple regression analysis.
a. State the regression equation.
b. Perform a residual analysis of the results and determine whether the regression assumptions are valid.
c. At the 0.05 level of significance, is there a significant relationship between the natural logarithm of calories and the percentage of alcohol and the number of carbohydrates?
d. Interpret the meaning of the coefficient of determination, r2, in this problem.
e. Compute the adjusted r2.
f. Compare your results with those in Problems 15.4 and 15.10. Which model is best? Why?