Effect evaluations of each factor under Plackett–Burman test designa.
| Potential CPPs | P-value | Significance |
|---|---|---|
| Model | <0.0001 | Extremely significant |
| X 1 | <0.0001 | Extremely significant |
| X 2 | 0.0142 | Significant |
| X 3 | 0.9588 | |
| X 4 | 0.0480 | Significant |
| X 5 | 0.1386 | |
| X 6 | 0.5273 |
Significant (P < 0.05); extremely significant (P < 0.01).