In studying the energy consumption of families, we have broken them into three groups. Group 1 consists of those who have enrolled in a time-of-day electrical-rate system (the charge per kilowatt-hour...

In studying the energy consumption of families, we have broken them into three groups. Group 1 consists of those who have enrolled in a time-of-day electrical-rate system (the charge per kilowatt-hour of electricity is higher during peak demand times of the day). Group 2 is made up of those who inquired into such a system but did not use it, and Group 3 represents those who have shown no interest in the system. We record the amount of the electrical bill per month for each household as our dependent variable (Y). As a covariate, we take the electrical bill for that household for the same month last year (C). The data follow:

a. Set up the design matrix.

b. Run the analysis of covariance.