Table 3.

ANOVA for response surface quadratic model

Source	Sum of squares	Degree of freedom	Mean Square	F-value	P-valuea
Model	18.99	9	2.11	328.55	< 0.0001
X1	0.042	1	0.042	6.52	0.0379
X2	0.25	1	0.25	39.13	0.0004
X3	0.002346	1	0.002346	0.37	0.5647
X1 × X2	0.30	1	0.30	46.50	0.0002
X1 × X3	0.27	1	0.27	42.58	0.0003
X2 × X3	0.045	1	0.045	7.03	0.0329
X1 × X1	2.91	1	2.91	452.34	< 0.0001
X2 × X2	10.04	1	10.04	1563.59	< 0.0001
X3 × X3	−0.90	1	−0.90	532.97	< 0.0001
Residual	0.045	7	0.006423
Pure Error	0.02	4	0.005101
Lack of Fit	0.025	3	0.008186	1.60	0.3216
R-Squared	0.997638

^aP < 0.01 highly significant; 0.01 ≤ P < 0.05 significant; P ≥ 0.05 not significant