Table 3.

ANOVA and significance level of response surface quadratic model

Source	Sum of squares	df	Mean square	F value	P value
Model#	4,654,620	9	517,180	108.05	< 0.0001
X1	31,164	1	31,164	6.51	0.029
X2	1,719,887	1	1,719,887	359.32	< 0.0001
X3	18,852	1	18,852	39.39	< 0.0001
X21	783,401	1	783,401	163.67	< 0.0001
X22	1,800,034	1	1,800,034	376.07	< 0.0001
X23	250,052	1	250,052	52.24	< 0.0001
X1 X2	3704	1	3704	0.77	0.4
X1 X3	57,856	1	57,856	12.09	0.006
X2 X3	191,489	1	191,489	40.01	< 0.0001
Residual	47,865	10	4786
Lack of fit	34,371	5	6874	2.55	0.164
Pure error	13,493	5	2699
Total	4,702,485	19

^#R² = 0.9898, R²(adj) = 0.9807, R²(pred) = 0.9401