MTB > read 'a:\ed257\grow.dat' c1-c2 21 ROWS READ ROW C1 C2 1 4 1 2 10 2 3 17 3 4 37 5 . . . MTB > describe c1-c2 N MEAN MEDIAN TRMEAN STDEV C1 21 117.9 107.0 118.1 69.6 C2 21 20.57 14.00 19.53 17.59 MIN MAX Q1 Q3 C1 4.0 228.0 75.0 176.0 C2 1.00 60.00 8.00 31.50 MTB > plot c1 c2 - 240+ - * * * C1 - * - * - 160+ * * - * - * - 2 - **** 80+ * - * - - * - 2 0+ * --+---------+---------+---------+---------+---------+----C2 0 12 24 36 48 60 MTB > corr c1 c2 Correlation of C1 and C2 = 0.943 MTB > brief 3 MTB > regress c1 1 c2 c3 c4; SUBC> residuals c5. The regression equation is C1 = 41.2 + 3.73 C2 Predictor Coef Stdev t-ratio p Constant 41.176 8.095 5.09 0.000 C2 3.7299 0.3021 12.34 0.000 s = 23.77 R-sq = 88.9% R-sq(adj) = 88.3% Analysis of Variance SOURCE DF SS MS F Regression 1 86074 86074 152.39 Error 19 10731 565 Total 20 96806 Obs. C2 C1 Fit Stdev.Fit Residual 1 1.0 4.00 44.91 7.87 -40.91 2 2.0 10.00 48.64 7.64 -38.64 3 3.0 17.00 52.37 7.42 -35.37 4 5.0 37.00 59.83 7.00 -22.83 5 7.0 65.00 67.29 6.61 -2.29 6 9.0 85.00 74.75 6.25 10.25 7 10.0 88.00 78.47 6.09 9.53 8 11.0 95.00 82.20 5.94 12.80 9 12.0 101.00 85.93 5.80 15.07 10 13.0 103.00 89.66 5.67 13.34 11 14.0 107.00 93.39 5.55 13.61 12 15.0 113.00 97.12 5.45 15.88 13 18.0 121.00 108.31 5.24 12.69 14 21.0 148.00 119.50 5.19 28.50 15 24.0 161.00 130.69 5.29 30.31 16 27.0 165.00 141.88 5.54 23.12 17 36.0 187.00 175.45 6.97 11.55 18 42.0 205.00 197.83 8.30 7.17 19 48.0 218.00 220.21 9.78 -2.21 20 54.0 218.00 242.59 11.35 -24.59 21 60.0 228.00 264.97 12.99 -36.97 X X denotes an obs. whose X gives it large influence. MTB > plot c5 c4 - - * * 25+ * - C5 - ***2 * - ** * - * 0+ * * - - - - -25+ * * - - * * - ** - --------+---------+---------+---------+---------+--------C4 50 100 150 200 250 MTB > describe c2 c12-c13 N MEAN MEDIAN TRMEAN STDEV C2 21 20.57 14.00 19.53 17.59 C12 21 718 196 604 1051 C13 21 31762 2744 23737 59536 MIN MAX Q1 Q3 C2 1.00 60.00 8.00 31.50 C12 1 3600 65 1012 C13 1 216000 536 33170 MTB > regress c1 2 c2 c12 c20 c21; SUBC> residuals c22. The regression equation is C1 = 3.86 + 8.32 C2 - 0.0796 C12 Predictor Coef Stdev t-ratio p Constant 3.862 4.369 0.88 0.388 C2 8.3206 0.4166 19.97 0.000 C12 -0.079580 0.006974 -11.41 0.000 s = 8.509 R-sq = 98.7% R-sq(adj) = 98.5% Analysis of Variance SOURCE DF SS MS F Regression 2 95503 47751 659.57 Error 18 1303 72 Total 20 96806 SOURCE DF SEQ SS C2 1 86074 C12 1 9428 Obs. C2 C1 Fit Stdev.Fit Residual 1 1.0 4.00 12.10 4.02 -8.10 2 2.0 10.00 20.19 3.70 -10.19 3 3.0 17.00 28.11 3.40 -11.11 4 5.0 37.00 43.48 2.89 -6.48 5 7.0 65.00 58.21 2.50 6.79 6 9.0 85.00 72.30 2.25 12.70 7 10.0 88.00 79.11 2.18 8.89 8 11.0 95.00 85.76 2.15 9.24 9 12.0 101.00 92.25 2.15 8.75 10 13.0 103.00 98.58 2.17 4.42 11 14.0 107.00 104.75 2.22 2.25 12 15.0 113.00 110.77 2.29 2.23 13 18.0 121.00 127.85 2.54 -6.85 14 21.0 148.00 143.50 2.81 4.50 15 24.0 161.00 157.72 3.03 3.28 16 27.0 165.00 170.50 3.20 -5.50 17 36.0 187.00 200.27 3.31 -13.27 18 42.0 205.00 212.95 3.25 -7.95 19 48.0 218.00 219.90 3.50 -1.90 20 54.0 218.00 221.12 4.48 -3.12 21 60.0 228.00 216.61 6.29 11.39 X X denotes an obs. whose X gives it large influence. MTB > plot c22 c21 C22 - - - * * 10+ * - * * - * - * * * - * * 0+ - * - * - * * * - * * -10+ * - * - * - +---------+---------+---------+---------+---------+------C21 0 40 80 120 160 200 MTB > regress c1 3 c2 c12 c13 c30 c31; SUBC> residuals c32. C12 is highly correlated with other predictor variables C13 is highly correlated with other predictor variables The regression equation is C1 = - 7.77 + 10.9 C2 - 0.199 C12 + 0.00139 C13 Predictor Coef Stdev t-ratio p Constant -7.766 3.675 -2.11 0.050 C2 10.9114 0.5833 18.70 0.000 C12 -0.19894 0.02421 -8.22 0.000 C13 0.0013857 0.0002760 5.02 0.000 s = 5.557 R-sq = 99.5% R-sq(adj) = 99.4% Analysis of Variance SOURCE DF SS MS F Regression 3 96281 32094 1039.46 Error 17 525 31 Total 20 96806 SOURCE DF SEQ SS C2 1 86074 C12 1 9428 C13 1 778 Obs. C2 C1 Fit Stdev.Fit Residual 1 1.0 4.00 2.95 3.20 1.05 2 2.0 10.00 13.27 2.78 -3.27 3 3.0 17.00 23.21 2.43 -6.21 4 5.0 37.00 41.99 1.91 -4.99 5 7.0 65.00 59.34 1.65 5.66 6 9.0 85.00 75.33 1.59 9.67 7 10.0 88.00 82.84 1.61 5.16 8 11.0 95.00 90.03 1.64 4.97 9 12.0 101.00 96.92 1.68 4.08 10 13.0 103.00 103.50 1.73 -0.50 11 14.0 107.00 109.80 1.77 -2.80 12 15.0 113.00 115.82 1.80 -2.82 13 18.0 121.00 132.26 1.88 -11.26 14 21.0 148.00 146.47 1.93 1.53 15 24.0 161.00 158.67 1.99 2.33 16 27.0 165.00 169.09 2.11 -4.09 17 36.0 187.00 191.86 2.73 -4.86 18 42.0 205.00 202.24 3.01 2.76 19 48.0 218.00 210.86 2.91 7.14 20 54.0 218.00 219.52 2.94 -1.52 21 60.0 228.00 230.02 4.90 -2.02 X R denotes an obs. with a large st. resid. X denotes an obs. whose X gives it large influence. MTB > plot c32 c31 - * - 7.0+ * - * ** C32 - * - * * - * * 0.0+ * - * * - * ** - * * - * * -7.0+ - - - * - +---------+---------+---------+---------+---------+------C31 0 50 100 150 200 250