Table 7 ANOVA for analysis of variance and adequacy of the response surface quadratic model for silica extraction for CCD obtained by the Design Expert 7.1 software.
Source of variation | Sum of square | DF | Mean square | F value | P value | Remarks |
|---|---|---|---|---|---|---|
Model | 10,033.25 | 9 | 1114.81 | 21.74 | < 0.0001 | S |
A | 360.00 | 1 | 360.00 | 7.02 | 0.0243 | S |
B | 504.10 | 1 | 504.10 | 9.83 | 0.0106 | S |
C | 281.96 | 1 | 281.96 | 5.50 | 0.0410 | S |
AB | 364.50 | 1 | 364.50 | 7.11 | 0.0236 | S |
AC | 450.00 | 1 | 450.00 | 8.78 | 0.0142 | S |
BC | 200.00 | 1 | 200.00 | 3.90 | 0.0765 | NS |
A2 | 4065.61 | 1 | 4065.61 | 79.30 | < 0.0001 | S |
B2 | 23.93 | 1 | 23.93 | 0.47 | 0.5100 | NS |
C2 | 2.75 | 1 | 2.75 | 0.054 | 0.8215 | NS |
Residual | 512.69 | 10 | 51.27 | |||
Lack of fit | 339.85 | 5 | 67.97 | 1.97 | 0.2379 | NS |
Pure error | 172.84 | 5 | 34.57 | |||
Correlation total | 10,545.94 | 19 |
