Regression Analysis: y versus x1, x2, x3, x4 The regression equation is y = - 123 + 0.757 x1 + 7.52 x2 + 2.48 x3 - 0.481 x4 Predictor Constant x1 x2 x3 x4 Coef -123.1 0.7573 7.519 2.483 -0.4811 S = 11.7866 SE Coef 157.3 0.2791 4.010 1.809 0.5552 R-Sq = 85.2% T -0.78 2.71 1.87 1.37 -0.87 P 0.459 0.030 0.103 0.212 0.415 R-Sq(adj) = 76.8% Analysis of Variance Source Regression Residual Error Total DF 4 7 11 SS 5600.5 972.5 6572.9 MS 1400.1 138.9 F 10.08 P 0.005 Correlations: y, x1, x2, x3, x4 y 0.803 0.002 x1 x2 0.827 0.001 0.660 0.019 x3 0.093 0.774 -0.288 0.365 0.113 0.727 x4 -0.133 0.681 -0.024 0.942 -0.025 0.938 x1 x2 x3 0.079 0.807 Stepwise Regression: y versus x1, x2, x3, x4 Forward selection. Alpha-to-Enter: 0.25 Response is y on 4 predictors, with N = 12 Step Constant 1 -100.518 2 3.916 3 -162.135 x2 T-Value P-Value 15.5 4.65 0.001 9.9 2.66 0.026 7.7 1.95 0.087 0.57 2.29 0.048 0.75 2.73 0.026 x1 T-Value P-Value x3 T-Value P-Value S R-Sq R-Sq(adj) Mallows Cp 2.3 1.32 0.223 14.4 68.39 65.23 7.0 12.1 80.04 75.61 3.4 11.6 83.62 77.47 3.8 Stepwise Regression: y versus x1, x2, x3, x4 Backward elimination. Alpha-to-Remove: 0.1 Response is y on 4 predictors, with N = 12 Step Constant 1 -123.131 2 -162.135 3 3.916 x1 T-Value P-Value 0.76 2.71 0.030 0.75 2.73 0.026 0.57 2.29 0.048 x2 T-Value P-Value 7.5 1.87 0.103 7.7 1.95 0.087 9.9 2.66 0.026 x3 T-Value P-Value 2.5 1.37 0.212 2.3 1.32 0.223 x4 T-Value P-Value -0.48 -0.87 0.415 S R-Sq R-Sq(adj) Mallows Cp 11.8 85.20 76.75 5.0 11.6 83.62 77.47 3.8 12.1 80.04 75.61 3.4 Best Subsets Regression: y versus x1, x2, x3, x4 Response is y Vars 1 1 2 2 3 3 4 R-Sq 68.4 64.4 80.0 75.8 83.6 81.2 85.2 R-Sq(adj) 65.2 60.8 75.6 70.5 77.5 74.2 76.8 Mallows Cp 7.0 8.8 3.4 5.4 3.8 4.9 5.0 S 14.415 15.295 12.072 13.287 11.602 12.420 11.787 x x x x 1 2 3 4 X X X X X X X X X X X X X X X X