Table 5.
Analysis of variance (ANOVA) for the response surface quadratic model.
| Source | Estimated coefficients | Sum of squares | Degree of freedom | Mean square | F-value | Prob. > F |
|---|---|---|---|---|---|---|
| Model | 0.3853 | 5.83E − 02 | 9 | 6.48E − 03 | 58.69 | <0.0001 |
| X 1 | 3.68E − 02 | 1.85E − 02 | 1 | 1.85E − 02 | 167.40 | <0.0001 |
| X 2 | 9.90E − 03 | 1.34E − 03 | 1 | 1.34E − 03 | 12.11 | 0.0059 |
| X 3 | 4.61E − 02 | 2.90E − 02 | 1 | 2.90E − 02 | 262.52 | <0.0001 |
| X 1 X 2 | 2.81E − 04 | 6.33E − 07 | 1 | 6.33E − 07 | 0.01 | 0.9411 |
| X 1 X 3 | −6.19E − 03 | 3.06E − 04 | 1 | 3.06E − 04 | 2.77 | 0.1270 |
| X 2 X 3 | 3.69E − 03 | 1.09E − 04 | 1 | 1.09E − 04 | 0.99 | 0.3439 |
| X 1 2 | −3.19E − 03 | 1.47E − 04 | 1 | 1.47E − 04 | 1.33 | 0.2758 |
| X 2 2 | −2.27E − 02 | 7.42E − 03 | 1 | 7.42E − 03 | 67.16 | <0.0001 |
| X 3 2 | −1.30E − 02 | 2.44E − 03 | 1 | 2.44E − 03 | 22.12 | 0.0008 |
| Residual | 1.10E − 03 | 10 | 1.10E − 04 | |||
| Lack of fit | 6.84E − 04 | 5 | 1.37E − 04 | 1.63 | 0.30 | |
| Pure error | 4.21E − 04 | 5 | 8.42E − 05 | |||
| Cor. total | 5.95E − 02 | 19 |