For countries listed in the Twelve Countries data file on the text CD, y = Internet use (percent) is predicted by x1 = per capita GDP (gross domestic product, in thousands of dollars) with r2 = 0.88. Adding x2 = carbon dioxide emissions per capita to the model yields the results in the following display.
Regression of Internet use on GDP and carbon dioxide emissions per capita

a. Report R2 and show how it is determined by SS values in the ANOVA table.
b. Interpret its value as a proportional reduction in prediction error.

Predictor Constant GDP CDE S-9.23490 Analysis of Variance Source Regression Residual Error Total Coef SE Coef 5.473 2.843 0.0021875 0.0002779 7.87 0.000 1.3849 0.52 0.616 0.7270 -1.90 0.089 R-Sq = 91.4% DF 8176.7 767.6 8944. 2