Gibberellic Acid Production from Corn Cob Residues via Fermentation with Aspergillus niger

Table 3

Analysis of variance (ANOVA) for the response surface quadratic model.

Source	DF	SS	MS (variance)	F
Total	11	234.37	21.31
Constant	1	214.99	214.99
Total corrected	10	19.38	1.94
Regression	4	19.21	4.80	176.55	0.000, significant
Residual	6	0.16	0.03
Lack of fit (model error)	4	0.15	0.04	5.09	0.171, not significant
Pure error (replicate error)	2	0.01	0.01