Table 3.

Analysis of variance (ANOVA) of quadratic polynomial model and significance test.

Source	Sum of squares	df	Mean square	F-value	p-value Prob > F	Significance
Model	27.45	27	1.02	11.18	<0.0001	Significant
Residual	2.18	24	0.091
Lack of fit	1.25	17	0.074	0.56	0.8475	Not significant
Pure error	0.93	7	0.13
Cor total	29.63	51