Table 8 Regression analysis of the heavy metal content of the samples
Model summary | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Model | R | R square | Adjusted R square | Std. error of the estimate | Change statistics | Durbin–Watson | ||||
R square change | F change | df1 | df2 | Sig. F change | ||||||
| Â | 0.836 | 0.698 | 0.640 | 132.18065 | 0.698 | 11.956 | 6 | 31 | 0.000 | 0.863 |
ANOVA | |||||
|---|---|---|---|---|---|
Model | Sum of squares | df | Mean square | F | Sig. |
Regression | 1,253,384.434 | 6 | 208,897.406 | 11.956 | 0.000b |
Residual | 541,623.431 | 31 | 17,471.724 | Â | Â |
Total | 1,795,007.865 | 37 | Â | Â | Â |
Coefficients | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Model | Unstandardized coefficients | Standardized coefficients | t | Sig. | 95.0% confidence interval for B | Correlations | Collinearity statistics | |||||
B | Std. error | Beta | Lower bound | Upper bound | Zero-order | Partial | Part | Tolerance | VIF | |||
(Constant) | 589.675 | 131.363 | Â | 4.489 | 0.000 | 321.758 | 857.593 | Â | Â | Â | Â | Â |
Ba | 8.814 | 1.608 | 0.694 | 5.481 | 0.000 | 5.534 | 12.094 | 0.736 | 0.702 | 0.541 | 0.607 | 1.647 |
Cr | −51.508 | 16.046 | −0.335 | −3.210 | 0.003 | −84.234 | −18.781 | −0.083 | −0.499 | −0.317 | 0.893 | 1.120 |
Fe | 0.097 | 0.252 | 0.048 | 0.386 | 0.702 | −0.417 | 0.612 | 0.387 | 0.069 | 0.038 | 0.640 | 1.561 |
Pb | 201.610 | 424.407 | 0.056 | 0.475 | 0.638 | −663.974 | 1067.194 | 0.338 | 0.085 | 0.047 | 0.689 | 1.451 |
Sr | −6.082 | 37.166 | −0.020 | −0.164 | 0.871 | −81.882 | 69.719 | 0.275 | −0.029 | −0.016 | 0.680 | 1.471 |
V | 16.486 | 8.954 | 0.251 | 1.841 | 0.075 | −1.776 | 34.748 | 0.509 | 0.314 | 0.182 | 0.522 | 1.916 |