Table 3. Analysis of variance for the initial model

Regression	DF	Type 1 sum of squares	R-square	F-value	p-value
Linear	5	1.601320	0.3190	3.83	0.0095
Quadratic	5	0.234238	0.0467	0.56	0.7296
2-Way interactions	10	0.926281	0.1845	1.11	0.3920
Total model	20	2.761839	0.5501	1.65	0.1116

Residual	DF	Sum of squares	Mean square	F-value	p-value
Lack of fit	22	2.225909	0.101178	15.48	0.0032
Pure error	5	0.032683	0.006537
Total error	27	2.258593	0.083652

DF, degrees of freedom.