Table 3.

ANOVA of experimental results of response surface methodology.

Source	Df	Sum of squares	Mean square	F value	P value (significant)
Model	9	1.22	0.13	175.17	<0.0001**
X1	1	0.41	0.41	532.99	<0.0001**
X2	1	0.0072	0.0072	9.37	0.0281*
X3	1	0.14	0.14	182.26	<0.0001**
X1X2	1	0.002025	0.002025	2.64	0.1654
X1X3	1	0.044	0.044	57.4	0.0006**
X2X3	1	0.000225	0.000225	0.29	0.6116
X12	1	0.26	0.26	333.24	<0.0001**
X22	1	0.31	0.31	406.48	<0.0001**
X32	1	0.12	0.12	161.52	<0.0001**
Lack of fit	3	0.003575	0.001192	8.94	0.1023
Pure error	2	0.0002667	0.0001333
Cor total	14	1.22

Notes: * and ** refer to differences that were significant at P < 0.05 and P < 0.01, respectively.

ANOVA: analysis of variance.