Table 3.

Fit summary of FCCD for silver nanoparticle biosynthesis by F. oxysporum as affected by incubation time (X₁), initial pH level (X₂), AgNO₃ conc. (X₃), and temperature (X₄).

Sequential Model Sum of Squares
Source	Sum of Squares	df	Mean Square	F-Value	p-Value Prob > F
Linear vs. Mean	2442.37	4	610.59	6.76	0.0008 *
2FI vs. Linear	2236.15	6	372.69	305.96	<0.0001 *
Quadratic vs. 2FI	0.45	4	0.11	0.07	0.9888
Lack of Fit Tests
Source	Sum of Squares	df	Mean Square	F-value	p-value Prob > F
Linear	2251.76	20	112.59	74.65	<0.0001 *
2FI	15.60	14	1.11	0.74	0.7005
Quadratic	15.15	10	1.51	1.00	0.5327
Model Summary Statistics
Source	Standard deviation	R-Squared	Adjusted R-Squared	Predicted R-Squared	PRESS
Linear	9.51	0.5195	0.4426	0.1346	4068.63
2FI	1.1	0.9951	0.9925	0.9794	96.74
Quadratic	1.23	0.9952	0.9907	0.9745	119.82

* Significant values, df: degree of freedom, PRESS: sum of squares of prediction error, two factors interaction: 2FI.