Table 2.
Estimated regression coefficients for the quadratic polynomial model and analyzes of variance (ANOVA) for the experimental results.
| Parameters | Estimated Coefficients |
Standard Error |
DF a | Sum of Squares |
F Ratio b | Prob > F |
|---|---|---|---|---|---|---|
| Model | 14 | 46971.996 | 43.8356 | <0.0001 | ||
| Intercept | 205.032 | 3.912523 | 52.40 | <0.0001 | ||
| Linear | ||||||
| X1-Ethanol | 10.99875 | 1.736676 | 1 | 2903.340 | 37.9327 | <0.0001 |
| X2-Time | 14.04375 | 1.736676 | 1 | 4733.446 | 61.8434 | <0.0001 |
| X3-Amplitude | −3.994583 | 1.736676 | 1 | 382.961 | 5.0035 | 0.0421 |
| X4-Ratio | 27.390417 | 1.736676 | 1 | 18005.638 | 235.2474 | <0.0001 |
| Quadratic | ||||||
| X1 2 | −1.526438 | 1.717541 | 1 | 60.454 | 0.7898 | 0.3892 |
| X2 2 | −11.56144 | 1.717541 | 1 | 3468.113 | 45.3116 | <0.0001 |
| X3 2 | −0.888938 | 1.717541 | 1 | 20.503 | 0.2679 | 0.6128 |
| X4 2 | −17.87644 | 1.717541 | 1 | 8291.469 | 108.3279 | <0.0001 |
| Interaction | ||||||
| X1–X2 | 5.049375 | 2.187167 | 1 | 407.939 | 5.3298 | 0.0367 |
| X1–X3 | −11.46062 | 2.187167 | 1 | 2101.535 | 27.4570 | <0.0001 |
| X1–X4 | −12.58812 | 2.187167 | 1 | 2535.37 | 33.1252 | <0.0001 |
| X2–X3 | 15.196875 | 2.187167 | 1 | 3695.120 | 48.2775 | <0.0001 |
| X2–X4 | −7.198125 | 2.187167 | 1 | 829.008 | 10.8312 | 0.0054 |
| X3–X4 | −6.580625 | 2.187167 | 1 | 692.874 | 9.0525 | 0.0094 |
| Lack of fit | 10 | 94.0987 | 4.550 | 0.0911 | ||
| Pure error | 4 | |||||
| R2 | 0.9776 | |||||
| Adjusted R2 | 0.9553 | |||||
| C.V. % | 3.71%. | |||||
| RMSE | 8.7186 | |||||
| CorTotal c | 28 | 48043.545 |
a Degree of freedom; b the model mean square to error mean square ratio; c corrected total. DF, degree of freedom; F Ratio, freedom ratio; Prob, probability; C.V., coefficient of variation.