Table 2.

ANOVA results of the first-order model for 2³ full factorial design.

Source of variation or factors	DFa	Sum of squares	Mean square	F or t value	P value
Modelb	7	10.75	1.54	14.09	0.0112
Curvature	7	0.43	0.43	0.071	0.1182
Pure error	4	0.44	0.11	3.94
Correlation total	12	11.61

^aDF: degree of freedom.

^b R ²: 96.10%.

Significant at α = 0.05.