Table 4.

Analysis of variance (ANOVA) for regression model.

Source	SSa	DF	MS	F	p
Model	481.38	9	53.49	174.13	<0.001
Linear	298.58	3	99.53	324.01	<0.001
Quadratic	155.85	3	51.95	169.12	<0.001
Interactions	26.95	3	8.98	29.24	0.001
Residual	1.54	5	0.31
Lack of fit	0.82	3	0.27	0.75	0.614
Pure error	0.72	2	0.36
Total SS	482.91	14
R 2 = 0.9968, Radj2 = 0.9911, Rpred2 = 0.9696.

^aSS: sum of squares; DF: degrees of freedom; MS: mean square; R²: determination coefficient; adj R²: adjusted R²; pred R²: predicted R².