14.17 Hamburger sales regression Refer to the previous exercise.

a. Set up indicator variables for a regression model so that an F test for the regression parameters is equivalent to the ANOVA test comparing the three means.

b. Express the null hypothesis both in terms of population means and in terms of regression parameters for the model in part a.

c. The prediction equation from fitting the multiple regression model equals yn = 1200 + 600x1 + 300x2.

Use this equation to find the predicted population means for each group.