Notice that X2 and Y2 are skewed. Taking the SQRT of Y2 reduces the skewness greatly. The MEANS Procedure Variable Mean Std Dev Minimum Maximum Skewness ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ X 48.5850000 9.9850529 16.0000000 74.0000000-0.0525127 Y 49.6550000 9.8473768 22.0000000 77.0000000-0.0687420 X2 45.6750000 27.1233804 1.0000000 144.0000000 1.0456103 Y2 48.4300000 27.4836653 3.0000000 163.0000000 0.9484129 Y2_SQRT 6.6750871 1.9729864 1.7320508 12.7671453 0.1711926 ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ ------------------------------------------------------------------------------------------------ Predicting Y from X. Number of Observations Read 200 Number of Observations Used 200 Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 1 4032.22920 4032.22920 52.30 <.0001 Error 198 15265 77.09579 Corrected Total 199 19297 Root MSE 8.78042 R-Square 0.2090 Dependent Mean 49.65500 Adj R-Sq 0.2050 Coeff Var 17.68285 Parameter Estimates Parameter Standard Variable DF Estimate Error t Value Pr > t Intercept 1 27.75229 3.09158 8.98 <.0001 X 1 0.45081 0.06234 7.23 <.0001
Predicting Y from X. ƒƒƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒƒƒ RESIDUAL 30 ˆ ˆ 20 ˆ ˆ 1 1 1 1 1 1 1 1 1 1 11 1 10 ˆ 1 1 1 11 1 1 ˆ 1 1 2 1 2 1 1 1 1 R 11 1 2 1 2 121 11 1 1 e 11 11 311 11 1 1 1 1 s 1 1 1 1111 1 1 2 1 1 i 1 2 1 1 2 2 12 1 1 d 0 ˆ 11 1 1 1 21 1 1 1 1 1 ˆ u 1 1 11 1 12 1 1 1 1 11 1 1 a 1 1 1 1 1 1 1 1 1 l 11 1 11 1 1 1 1 21 1 1 1 1 12 1 3 1 1 1 1 1 1 1 1 1 1-10 ˆ 1 1 1 1 1 1 ˆ 1 1 11 1 12 1 11 1 1 1 1 11 1 1 1 1 1 1-20 ˆ 1 1 ˆ -30 ˆ ˆ ŠƒƒƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒƒƒŒ 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 Predicted Value of Y PRED
Distribution of the residuals is normal. The UNIVARIATE Procedure Variable: Y_Resid (Residual) Moments N 200 Sum Weights 200 Mean 0 Sum Observations 0 Std Deviation 8.75833151 Variance 76.7083708 Skewness -0.073839 Kurtosis -0.2635309 Tests for Normality Test --Statistic--- -----p Value------ Shapiro-Wilk W 0.995522 Pr < W 0.8233 Kolmogorov-Smirnov D 0.041479 Pr > D >0.1500 Cramer-von Mises W-Sq 0.050073 Pr > W-Sq >0.2500 Anderson-Darling A-Sq 0.294818 Pr > A-Sq >0.2500 ------------------------------------------------------------------------------------------------ Stem Leaf # Boxplot 22 3 1 20 9 1 18 0 1 16 395 3 14 178055 6 12 25 2 10 166990167 9 8 067788902248 12 6 0002358889901244666 19 +-----+ 4 01223335678915568 17 2 0111125580233456789 19 0 01123448001229 14 *--+--* -0 888764439973111 15-2 998875543211 12-4 999976421099876654100 21 +-----+ -6 98832976110 11-8 9727210 7-10 87642219541 11-12 785520 6-14 841963 6-16 7452 4-18 -20 63 2-22 4 1 ----+----+----+----+-
Predicting Y from skewed X2. Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 1 3913.33497 3913.33497 50.37 <.0001 Error 198 15384 77.69626 Corrected Total 199 19297 Root MSE 8.81455 R-Square 0.2028 Dependent Mean 49.65500 Adj R-Sq 0.1988 Coeff Var 17.75158 Parameter Estimates Parameter Standard Variable DF Estimate Error t Value Pr > t Intercept 1 42.18739 1.22297 34.50 <.0001 X2 1 0.16349 0.02304 7.10 <.0001
Predicting Y from skewed X2. ƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒ RESIDUAL 30 ˆ ˆ 20 ˆ ˆ 1 1 1 1 1 1 1 1 1 1 1 2 1 10 ˆ 11 1 1 2 1 1 1 ˆ 2 111 2 1 1 1 1 1 R 1 1 12 1 11 11 1 1 1 e 1 2111 2 12 1 1 1 1 1 s 111 1 2 1 1 21 1 1 1 i 1 1 1 11 11 1 1 1 d 0 ˆ 1 21 2 3 1 1 1 1 1 ˆ u 111 1 1 1 1 11 1 1 1 1 1 a 2 11 1 11 1 1 1 1 l 1 1 12 1 4 1 1 12 1 1 11 1 1 11 1 1 1 1 1 1 1 1-10 ˆ 1 11 1 1 1 1 1 1 ˆ 1 11 1 1 11 11 1 1 1 1 1 2 1 1 1 1 1 1-20 ˆ 1 1 ˆ -30 ˆ ˆ ŠƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒˆƒƒƒƒƒŒ 42 44 46 48 50 52 54 56 58 60 62 64 66 Predicted Value of Y PRED
Distribution of the residuals is normal. The UNIVARIATE Procedure Variable: Y_Resid (Residual) Moments N 200 Sum Weights 200 Mean 0 Sum Observations 0 Std Deviation 8.79237336 Variance 77.3058293 Skewness -0.0663383 Kurtosis -0.2895344 Tests for Normality Test --Statistic--- -----p Value------ Shapiro-Wilk W 0.99566 Pr < W 0.8413 Kolmogorov-Smirnov D 0.042296 Pr > D >0.1500 Cramer-von Mises W-Sq 0.048393 Pr > W-Sq >0.2500 Anderson-Darling A-Sq 0.290731 Pr > A-Sq >0.2500 Stem Leaf # Boxplot 22 76 2 20 18 23 2 16 2 1 14 48967 5 12 2362 4 10 1579246789 10 8 01466234666 11 6 0033366791226668899 19 +-----+ 4 22233445679134589 17 2 357889224678999 15 0 12225778912226679 17 *--+--* -0 98887544310744322 17-2 997433886420 12-4 8875442220954333210 19 +-----+ -6 8531175444 10-8 76428441 8-10 887543111985430 15-12 83 2-14 846511 6-16 94621 5-18 4 1-20 1 1-22 1 1 ----+----+----+----+
Predicting skewed Y from X. 2 Number of Observations Read 200 Number of Observations Used 200 Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 1 30674 30674 50.76 <.0001 Error 198 119641 604.24645 Corrected Total 199 150315 Root MSE 24.58142 R-Square 0.2041 Dependent Mean 48.43000 Adj R-Sq 0.2000 Coeff Var 50.75661 Parameter Estimates Parameter Standard Variable DF Estimate Error t Value Pr > t Intercept 1-11.98045 8.65509-1.38 0.1679 X 1 1.24340 0.17451 7.12 <.0001
Predicting skewed Y from X. 2 ƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒ RESIDUAL 100 ˆ ˆ 80 ˆ 1 ˆ 60 ˆ ˆ 1 1 1 40 ˆ 1 1 1 1 1 ˆ R 1 1 1 e 1 1 1 1 s 1 1 1 1 1 1 i 1 1 2 1 1 1 d 20 ˆ 1 1 2 1 1 ˆ u 1 1 1 1 1 1 2 1 11 1 a 1 12 1 1 1 1 l 1111 11 1 1 1 1 1 1 1 1 1 111 1 1 1 2 1 0 ˆ 1 11 1 2 1 1 2 2 1 1 1 ˆ 1 1 1 2 1 1 1 1 1 12 1 2 11 1 1 1 1 121 1 111 1 1 1 1 1 1 1 1 12 111 1 11 11 1-20 ˆ 1 2 3 1 112 1 ˆ 2111 11 1 1 1 11 1 2 1 1 1 1 1 1 1 1 2 1 11 1 1 1 1 1-40 ˆ 1 1 1 ˆ -60 ˆ ˆ ŠƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒŒ 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 Predicted Value of Y2 PRED
Distribution of the residuals is skewed. The UNIVARIATE Procedure Variable: Y_Resid (Residual) Moments N 200 Sum Weights 200 Mean 0 Sum Observations 0 Std Deviation 24.5195847 Variance 601.210036 Skewness 0.80271812 Kurtosis 0.96531758 Uncorrected SS 119640.797 Corrected SS 119640.797 Coeff Variation. Std Error Mean 1.73379646 Tests for Normality Test --Statistic--- -----p Value------ Shapiro-Wilk W 0.961907 Pr < W <0.0001 Kolmogorov-Smirnov D 0.064107 Pr > D 0.0438 Cramer-von Mises W-Sq 0.196838 Pr > W-Sq 0.0058 Anderson-Darling A-Sq 1.363844 Pr > A-Sq <0.0050 ------------------------------------------------------------------------------------------------ Stem Leaf # Boxplot 8 249 3 0 7 6 5 2467 4 4 1112238 7 3 13345679 8 2 1122233444778999 16 1 001122334455555666677889 24 +-----+ 0 01111122223344455555666777888889 32 + -0 99888877775544444432222111 26 *-----* -1 999888888887777776666544433222111111100 39 +-----+ -2 9977777766665443322110 22-3 9987644322221110 16-4 631 3 ----+----+----+----+----+----+----+---- Multiply Stem.Leaf by 10**+1
Predicting transformed Y2 from X. 2_SQRT Number of Observations Read 200 Number of Observations Used 200 Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 1 163.14571 163.14571 52.83 <.0001 Error 198 611.49665 3.08837 Corrected Total 199 774.64236 Root MSE 1.75738 R-Square 0.2106 Dependent Mean 6.67509 Adj R-Sq 0.2066 Coeff Var 26.32737 Parameter Estimates Parameter Standard Variable DF Estimate Error t Value Pr > t Intercept 1 2.26941 0.61877 3.67 0.0003 X 1 0.09068 0.01248 7.27 <.0001
Predicting transformed Y2 from X. 2_SQRT ƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒ RESIDUAL 6 ˆ ˆ 4 ˆ 1 1 ˆ 1 1 1 1 1 R 1 1 1 1 2 e 2 ˆ 1 1 1 1 1 1 1 1 1 ˆ s 1 1 1 2 1 2 1 1 i 11 1 1 1 1 121 11 1 1 d 1 131 11 1 1 1 1 1 u 1 1 2 1121 1 1 1 1 2 1 1 a 1 1 1 2 1 1 2 1 1 l 0 ˆ 11 1 2 1 2 11 1 1 1 1 1 ˆ 1 1 1 1 2 1 1 11 1 1 11 1 11 11 1 1 1 1 11 1 111 1 11 211 11 1 1 1 12 1 3 1 11 1 1 11 1 1 1 1-2 ˆ 1 111 1 1 1 1 ˆ 1 1 1 1 12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1-4 ˆ 1 ˆ ŠƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒŒ 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 Predicted Value of Y2_SQRT PRED
Distribution of the residuals is nearly normal. The UNIVARIATE Procedure Variable: Y_Resid (Residual) Moments N 200 Sum Weights 200 Mean 0 Sum Observations 0 Std Deviation 1.75295393 Variance 3.07284748 Skewness 0.13316606 Kurtosis -0.2395222 Tests for Normality Test --Statistic--- -----p Value------ Shapiro-Wilk W 0.994031 Pr < W 0.6051 Kolmogorov-Smirnov D 0.037527 Pr > D >0.1500 Cramer-von Mises W-Sq 0.028558 Pr > W-Sq >0.2500 Anderson-Darling A-Sq 0.204974 Pr > A-Sq >0.2500 ------------------------------------------------------------------------------------------------ Distribution of the residuals is nearly normal. The UNIVARIATE Procedure Variable: Y_Resid (Residual) Stem Leaf # Boxplot 5 0 1 4 8 1 4 3 5799 4 3 01112 5 2 569 3 2 11112223344 11 1 555566778888899 15 1 00011112223333333344 20 +-----+ 0 5666666677778888888999 22 0 0111122333334444 16 + -0 4444433333221111111100 22 *-----* -0 99987666666555 14-1 4443333322222111100000000 25 +-----+ -1 99877766555 11-2 444433332221100 15-2 9988866 7-3 43211 5-3 986 3 ----+----+----+----+----+
New Data Set. The MEANS Procedure Variable Mean Std Dev Skewness ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ Y 92.2400000 12.1248722 0.0211379 X 20.0000000 14.2133811 0 ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ ------------------------------------------------------------------------------------------------ Predict Y from X. Number of Observations Read 100 Number of Observations Used 100 Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 1 174.84500 174.84500 1.19 0.2777 Error 98 14379 146.72852 Corrected Total 99 14554 Root MSE 12.11315 R-Square 0.0120 Dependent Mean 92.24000 Adj R-Sq 0.0019 Coeff Var 13.13221 Parameter Estimates Parameter Standard Variable DF Estimate Error t Value Pr > t Intercept 1 90.37000 2.09806 43.07 <.0001 X 1 0.09350 0.08565 1.09 0.2777
Predict Y from X. ˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒ RESIDUAL 30 ˆ ˆ 2 2 20 ˆ 3 ˆ 1 1 1 2 1 10 ˆ 3 ˆ 3 1 2 R e 2 2 2 1 s 1 3 1 1 2 i 2 2 d 0 ˆ 1 2 2 ˆ u 1 1 3 1 a 2 2 l 2 2 1 1 1 1 3-10 ˆ 2 3 ˆ 1 1 5 1 1 2 1 3-20 ˆ ˆ 2-30 ˆ ˆ ŠˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒƒƒƒƒƒƒƒˆƒŒ 90.0 90.5 91.0 91.5 92.0 92.5 93.0 93.5 94.0 94.5 Predicted Value of Y PRED
Marginal distribution of residuals does not show the problem. The UNIVARIATE Procedure Variable: residuals (Residual) Moments N 100 Sum Weights 100 Mean 0 Sum Observations 0 Std Deviation 12.051822 Variance 145.246414 Skewness 0.04651058 Kurtosis -0.1088063 Tests for Normality Test --Statistic--- -----p Value------ Shapiro-Wilk W 0.990678 Pr < W 0.7193 Kolmogorov-Smirnov D 0.045974 Pr > D >0.1500 Cramer-von Mises W-Sq 0.024687 Pr > W-Sq >0.2500 Anderson-Darling A-Sq 0.218939 Pr > A-Sq >0.2500 Stem Leaf # Boxplot 2 559 3 2 01134 5 1 5558 4 1 11112444 8 0 555556677889999 15 +-----+ 0 11112233344444 14 + -0 44443333221111000 17 *-----* -0 99987666655 11 +-----+ -1 33322211111100 14-1 7765 4-2 43 2-2 866 3 ----+----+----+----+ Multiply Stem.Leaf by 10**+1
Polynomial regression: Quadratic. Number of Observations Read 100 Number of Observations Used 100 Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 2 6275.73429 3137.86714 36.77 <.0001 Error 97 8278.50571 85.34542 Corrected Total 99 14554 Root MSE 9.23826 R-Square 0.4312 Dependent Mean 92.24000 Adj R-Sq 0.4195 Coeff Var 10.01546 Parameter Estimates Parameter Standard Variable DF Estimate Error t Value Pr > t Intercept 1 99.70571 1.94411 51.29 <.0001 X 1-1.77364 0.23030-7.70 <.0001 X_SQ 1 0.04668 0.00552 8.45 <.0001
Polynomial regression: Quadratic. ƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒ RESIDUAL 20 ˆ 1 1 ˆ 1 2 1 1 1 1 2 10 ˆ 2 2 1 ˆ 1 1 1 1 2 2 1 2 3 2 1 3 R 1 2 2 3 1 e 0 ˆ 2 2 1 3 ˆ s 4 1 3 3 i 4 1 1 d 2 2 2 u 2 1 1 1 a 2 1 1 2 l -10 ˆ 1 2 ˆ -20 ˆ 1 1 ˆ 2 1-30 ˆ ˆ ŠƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒŒ 82 84 86 88 90 92 94 96 98 100 102 104 Predicted Value of Y PRED
Polynomial regression: Quadratic. ƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒƒ Y 130 ˆ ˆ 120 ˆ. ˆ.. 110 ˆ.. ˆ...... X.. 100 ˆ?... ˆ.............. 90 ˆ.... ˆ..??...?.. 80 ˆ.... ˆ 70 ˆ ˆ 60 ˆ ˆ ŠƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒˆƒƒƒƒƒŒ 0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 37.5 40.0 X
------------------------------------------------------------------------------------------------ Another new data set. The MEANS Procedure Variable Mean Std Dev Minimum Maximum Skewness ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ X 34.4500000 8.8401242 7.0000000 60.0000000-0.0533010 Y 644.6480000 193.9131783 83.0000000 1457.00 0.3953723 ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ ------------------------------------------------------------------------------------------------ Heteroscedasticity. Number of Observations Read 500 Number of Observations Used 500 Analysis of Variance Sum of Mean Source DF Squares Square F Value Pr > F Model 1 3289612 3289612 105.87 <.0001 Error 498 15473946 31072 Corrected Total 499 18763558 Root MSE 176.27303 R-Square 0.1753 Dependent Mean 644.64800 Adj R-Sq 0.1737 Coeff Var 27.34407 Parameter Estimates Parameter Standard Variable DF Estimate Error t Value Pr > t Intercept 1 328.23603 31.74586 10.34 <.0001 X 1 9.18467 0.89264 10.29 <.0001
Heteroscedasticity. ƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒ RESIDUAL 600 ˆ.. ˆ.. 400 ˆ.. ˆ..................................... 200 ˆ............. ˆ.................. R.............. e....................... s.................... i....................... d 0 ˆ........................... ˆ u...................... a..................... l..................................................... -200 ˆ............. ˆ................................... -400 ˆ. ˆ..... -600 ˆ. ˆ ŠƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒƒƒƒˆƒƒƒŒ 350 400 450 500 550 600 650 700 750 800 850 900 Predicted Value of Y PRED