Table 6.
Sequential model fitting for the total phenolic content.
| Source | Sum of squares | Mean square | DF | F-value | P-value | Remarks |
|---|---|---|---|---|---|---|
| Sequential sum of squares | ||||||
| Mean | 1.140E + 005 | 1.140E + 005 | 1 | |||
| Linear | 565.89 | 188.63 | 3 | 1.14 | 0.3684 | |
| 2F | 234.96 | 78.32 | 3 | 0.41 | 0.7494 | |
| Quadratic | 1693.57 | 564.52 | 3 | 18.24 | 0.0011* | Suggested |
| Cubic | 19.84 | 6.61 | 3 | 0.13 | 0.9345 | Aliased |
| Residual | 196.83 | 49.21 | 4 | |||
| Total | 1.167E + 005 | 6862.46 | 17 | |||
| Lack of fit tests | ||||||
| Linear | 1948.37 | 216.49 | 9 | 4.40 | 0.0837 | |
| 2F | 1713.41 | 285.57 | 6 | 5.80 | 0.0553 | |
| Quadratic | 19.84 | 6.61 | 3 | 0.13 | 0.9345 | Suggested |
| Cubic | 0.000 | 0 | Aliased | |||
| Pure error | 196.83 | 49.21 | 4 | |||
| Std. Dev | R-Squared | Adjusted R-Squared |
Predicted R-Squared |
PRESS | ||
|---|---|---|---|---|---|---|
| Model summary statistics source | ||||||
| Linear | 12.85 | 0.2087 | 0.0261 | − 0.5618 | 4234.10 | |
| 2F | 13.82 | 0.2954 | − 0.1274 | − 2.2271 | 8748.79 | |
| Quadratic | 5.56 | 0.9201 | 0.8173 | 0.7695 | 624.92 | Suggested |
| Cubic | 7.01 | 0.9274 | 0.7096 | + | Aliased | |
*statistically significant: p ˂ 0.05.