Open Access
Table 5
Regression coefficients for curve fit by quadratic model without constant.
| β1 | Chi-Q. | p | β2 | Chi-Q. | p | |
|---|---|---|---|---|---|---|
| Road | −0.06479 | 35.631 | 0.000 | 0.00213 | 76.089 | 0.000 |
| Rail | −0.04685 | 33.458 | 0.000 | 0.00159 | 52.745 | 0.000 |
| Air | −0.02447 | 3.973 | 0.046 | 0.00219 | 25.978 | 0.000 |
Note: β1 = regression coefficient for the 1st order; β2 = regression coefficient for the 2nd order; Chi-Q. = Wald-Chi-Quadrat; p = significance level; p < 0.05 is marked in bold.
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