Table 4. Analysis of variance for the response surface quadratic model.
| Source | Sum of squares | DF | Mean square | F value | P value |
|---|---|---|---|---|---|
| Model | 122.67 | 9 | 13.63 | 23.97 | 0.0002** |
| A | 3.65 | 1 | 3.65 | 6.41 | 0.0391* |
| B | 3.84 | 1 | 3.84 | 6.75 | 0.0356* |
| C | 22.85 | 1 | 22.85 | 40.18 | 0.0004** |
| AB | 0.20 | 1 | 0.20 | 0.36 | 0.5695 |
| AC | 3.53 | 1 | 3.53 | 6.22 | 0.0414* |
| BC | 3.31 | 1 | 3.31 | 5.82 | 0.0465* |
| A2 | 17.90 | 1 | 17.90 | 31.48 | 0.0008** |
| B2 | 23.89 | 1 | 23.89 | 42.01 | 0.0003** |
| C2 | 34.73 | 1 | 34.73 | 61.07 | 0.0001** |
| Residual | 3.98 | 7 | 0.57 | ||
| Lack of fit | 3.01 | 3 | 1.00 | 4.15 | 0.1051 |
| Pure error | 0.97 | 4 | 0.24 | ||
| Cor total | 126.65 | 16 |
Notes.
- DF
- degree of freedom
- Cor total
- totals of all information corrected for the mean
*
Significant at P < 0.05.
**
Highly significant at P < 0.01.