本人对附件所示数据进行Stepwise 回归分析,结果如下:请问X8在每个模型的系数均为0,如何解释?若为0,为何引入呢?这是不是跟minitab的有效数字设置有关?如有关,应在哪里设置呢? 请教各位!
步骤 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
常量 | 0.05265 | 0.12276 | 0.13814 | 0.15814 | 0.14806 | 0.53739 | 0.6113 | 0.6181 |
x13 | 1.01 | 1.73 | 1.19 | 1.13 | 1.11 | 1.03 | 1.14 | 1.13 |
T 值 | 5.37 | 12.33 | 4.74 | 4.66 | 4.75 | 5.3 | 6.79 | 6.66 |
P 值 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
x14 | -0.0207 | -0.0264 | -0.0286 | -0.0377 | -0.0212 | -0.0142 | -0.0125 | |
T 值 | -7.89 | -8.02 | -8.42 | -6.22 | -3.1 | -4.13 | -3.96 | |
P 值 | 0 | 0 | 0 | 0 | 0.005 | 0 | 0.001 | |
x5 | 1.5 | 1.56 | 2.28 | 0.82 | ||||
T 值 | 2.53 | 2.73 | 3.35 | 1.17 | ||||
P 值 | 0.018 | 0.011 | 0.003 | 0.252 | ||||
x8 | 0 | 0 | 0 | 0 | ||||
T 值 | -1.8 | -2.22 | -1.52 | -1.21 | ||||
P 值 | 0.084 | 0.035 | 0.141 | 0.239 | ||||
x6 | 0.00003 | 0.00032 | 0.00036 | 0.00037 | ||||
T 值 | 1.78 | 3.92 | 5.11 | 5.24 | ||||
P 值 | 0.087 | 0.001 | 0 | 0 | ||||
x1 | -0.0228 | -0.0272 | -0.0281 | |||||
T 值 | -3.58 | -5.24 | -5.43 | |||||
P 值 | 0.002 | 0 | 0 | |||||
S | 0.0468 | 0.0265 | 0.0243 | 0.0233 | 0.0224 | 0.0185 | 0.0186 | 0.0188 |
R-Sq | 49.89 | 84.45 | 87.43 | 88.82 | 90.08 | 93.53 | 93.16 | 92.76 |
R-Sq(调整) | 48.17 | 83.34 | 86.03 | 87.1 | 88.1 | 91.91 | 91.79 | 91.65 |
Mallows Cp | 153.1 | 30.9 | 22.2 | 19.2 | 16.7 | 6.3 | 5.6 | 5 |