--------------------------------------------------------------------------------------------------------- log: D:\My Documents\My Downloads\Econ 170\chapter 11, question 4.log log type: text opened on: 9 Nov 2005, 21:50:46 . use "E:\Schmidt\(02) Stata Format\buscost2.dta", clear . summarize private Variable | Obs Mean Std. Dev. Min Max -------------+-------------------------------------------------------- private | 246 .0691057 .2541509 0 1 . regress totalcost plabor padmin pmaint pfuel rvm private variable totalcost not found r(111); . regress opexp plabor padmin pmaint pfuel rvm private Source | SS df MS Number of obs = 243 -------------+------------------------------ F( 6, 236) = 330.11 Model | 8.0271e+10 6 1.3378e+10 Prob > F = 0.0000 Residual | 9.5643e+09 236 40526840.4 R-squared = 0.8935 -------------+------------------------------ Adj R-squared = 0.8908 Total | 8.9835e+10 242 371219273 Root MSE = 6366.1 ------------------------------------------------------------------------------ opexp | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- plabor | 455.9957 159.6195 2.86 0.005 141.5347 770.4567 padmin | 8.345672 17.7613 0.47 0.639 -26.64527 43.33662 pmaint | -7.439429 8.235028 -0.90 0.367 -23.66298 8.784126 pfuel | 1722.503 2701.375 0.64 0.524 -3599.387 7044.393 rvm | 4.931979 .1237683 39.85 0.000 4.688147 5.175811 private | -3249.935 1707.974 -1.90 0.058 -6614.758 114.8877 _cons | -7608.251 2673.288 -2.85 0.005 -12874.81 -2341.695 ------------------------------------------------------------------------------ . regress opexp plabor rvm private pfuel pmaint Source | SS df MS Number of obs = 243 -------------+------------------------------ F( 5, 237) = 397.40 Model | 8.0262e+10 5 1.6052e+10 Prob > F = 0.0000 Residual | 9.5733e+09 237 40393595.5 R-squared = 0.8934 -------------+------------------------------ Adj R-squared = 0.8912 Total | 8.9835e+10 242 371219273 Root MSE = 6355.6 ------------------------------------------------------------------------------ opexp | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- plabor | 463.4979 158.5576 2.92 0.004 151.1356 775.8602 rvm | 4.934926 .1234059 39.99 0.000 4.691814 5.178039 private | -3421.264 1665.854 -2.05 0.041 -6703.037 -139.4916 pfuel | 1742.253 2696.604 0.65 0.519 -3570.122 7054.628 pmaint | -7.246515 8.211255 -0.88 0.378 -23.42288 8.929855 _cons | -7304.877 2589.882 -2.82 0.005 -12407.01 -2202.747 ------------------------------------------------------------------------------ . regress opexp plabor rvm private pmaint Source | SS df MS Number of obs = 243 -------------+------------------------------ F( 4, 238) = 497.86 Model | 8.0245e+10 4 2.0061e+10 Prob > F = 0.0000 Residual | 9.5901e+09 238 40294721.8 R-squared = 0.8932 -------------+------------------------------ Adj R-squared = 0.8915 Total | 8.9835e+10 242 371219273 Root MSE = 6347.8 ------------------------------------------------------------------------------ opexp | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- plabor | 463.0089 158.3616 2.92 0.004 151.0394 774.9784 rvm | 4.923163 .1219058 40.38 0.000 4.68301 5.163315 private | -3301.479 1653.478 -2.00 0.047 -6558.8 -44.15872 pmaint | -5.773269 7.878636 -0.73 0.464 -21.29404 9.747497 _cons | -6076.858 1757.071 -3.46 0.001 -9538.255 -2615.461 ------------------------------------------------------------------------------ . regress opexp plabor rvm private Source | SS df MS Number of obs = 246 -------------+------------------------------ F( 3, 242) = 675.88 Model | 8.0599e+10 3 2.6866e+10 Prob > F = 0.0000 Residual | 9.6195e+09 242 39750199.9 R-squared = 0.8934 -------------+------------------------------ Adj R-squared = 0.8921 Total | 9.0219e+10 245 368239382 Root MSE = 6304.8 ------------------------------------------------------------------------------ opexp | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- plabor | 453.3491 156.4248 2.90 0.004 145.2212 761.477 rvm | 4.915487 .1206788 40.73 0.000 4.677772 5.153202 private | -3581.66 1600.279 -2.24 0.026 -6733.913 -429.4069 _cons | -6122.546 1718.322 -3.56 0.000 -9507.323 -2737.77 ------------------------------------------------------------------------------ . generate float rvm2=rvm^2 . regress opexp plabor rvm private rvm2 Source | SS df MS Number of obs = 246 -------------+------------------------------ F( 4, 241) = 507.53 Model | 8.0645e+10 4 2.0161e+10 Prob > F = 0.0000 Residual | 9.5736e+09 241 39724546.3 R-squared = 0.8939 -------------+------------------------------ Adj R-squared = 0.8921 Total | 9.0219e+10 245 368239382 Root MSE = 6302.7 ------------------------------------------------------------------------------ opexp | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- plabor | 487.0241 159.4793 3.05 0.003 172.8728 801.1754 rvm | 4.59536 .3212226 14.31 0.000 3.962597 5.228122 private | -3515.777 1600.935 -2.20 0.029 -6669.388 -362.165 rvm2 | .0000218 .0000202 1.08 0.283 -.0000181 .0000616 _cons | -6084.686 1718.128 -3.54 0.000 -9469.152 -2700.221 ------------------------------------------------------------------------------ . log close log: D:\My Documents\My Downloads\Econ 170\chapter 11, question 4.log log type: text closed on: 9 Nov 2005, 22:00:43 ---------------------------------------------------------------------------------------------------------