1. A developer wants to claim that his new "green" home design results in lower electricity use than in conventional homes. His 2,000 square foot model home uses 1,200 kilowatt hours per month on average. The Excel file Electric.xls in Files and Documents contains data on home size (in square feet) and average monthly electricity usage (in kilowatt hours) for a sample of conventional homes. Use this data to evaluate whether the developer's claim would be justified.
(a) Develop a simple regression model that relates electricity usage to home size. What is the resulting regression equation?
(b) Is this a good model? How can you tell?
(c) What would the model predict the average monthly electricity usage to be for a 2,000 square foot house, and how does this compare to the developer's model home's actual usage?
Monthly Electrical Usage for Various Home Sizes
Home_Size Monthly_Usage
1,710 1,571
1,290 1,182
2,930 1,954
2,230 1,840
1,840 1,711
2,400 1,956
1,980 1,804
1,470 1,264
1,600 1,493
1,350 1,172