Fuel Economy. For Exercises 60–67, refer to the table of fuel economy data from Exercises 80–84 in Section 4.2. The predictor variable is , expressed in liters; the response variable is , expressed in miles per gallon (mpg).
67. Challenge Exercise. Refer to the previous exercise. Describe how this change to the fuel economy of the Cadillac limousine would affect each of the following, and why: SSE, SSR, SST, , , .
4.3.67
Since , the regression equation is . Thus for all of the . Hence SSR = 0, so SSR would decrease. Since SST = SSR + SSE and SSR = 0, SSE = SST = 358.5622634, so both SSE and SST increase. Since the regression line doesn't include any information from the -values, SSR = 0, , and . Since , and and . Since and SSE increases, increases.