Table 3. ANOVA for response surface quadratic model analysis of variance table.

Source	Sum of squares	Degree of freedom	Mean square	F-value	p-value
Model	6597.89	9	733.10	237.17	< 0.0001**
X1	677.12	1	677.12	219.06	< 0.0001**
X2	534.65	1	534.65	172.97	< 0.0001**
X3	315.01	1	315.01	101.91	< 0.0001**
X1X2	69.72	1	69.72	22.56	0.0021**
X1X3	83.72	1	83.72	27.09	0.0012**
X2X3	12.60	1	12.60	4.08	0.0832
X12	949.58	1	949.58	307.21	< 0.0001**
X22	2741.65	1	2741.65	886.98	< 0.0001**
X32	752.38	1	752.38	243.41	< 0.0001**
Residual	21.64	7	3.09
Lack of Fit	15.89	3	5.30	3.68	0.1201
Pure Error	5.75	4	1.44
Cor Total	6619.53	16

** Significance with p < 0.01