Table 5 Variance analysis of regression equation for the extraction yield
Source | Sum of squares | Degree of freedom | Mean square | F-value | p value |
|---|---|---|---|---|---|
Regression model | 16.90 | 9 | 1.88 | 6.05 | 0.0135* |
X1 | 1.37 | 1 | 1.37 | 4.42 | 0.0737 |
X2 | 0.22 | 1 | 0.22 | 0.70 | 0.4320 |
X3 | 0.29 | 1 | 0.29 | 0.92 | 0.3693 |
X1X2 | 1.18 | 1 | 1.18 | 3.81 | 0.0920 |
X1X3 | 0.04 | 1 | 0.04 | 0.13 | 0.7305 |
X2X3 | 0.31 | 1 | 0.31 | 0.98 | 0.3544 |
X 21 | 8.57 | 1 | 8.57 | 27.62 | 0.0012* |
X 22 | 3.40 | 1 | 3.40 | 10.95 | 0.0129* |
X 23 | 0.48 | 1 | 0.48 | 1.56 | 0.2519 |
Residual error | 2.17 | 7 | 0.31 | ||
Lack of Fit | 1.04 | 3 | 0.35 | 1.23 | 0.4088 |
Pure error | 1.13 | 4 | 0.28 | ||
Total | 19.08 | 16 | |||
R2 = 0.9871 |