Table 2.

The values of regression coefficients and analysis of the model for extraction yield.

Parameter	Coefficient Estimate	Standard Error	Sum of Squares	Degrees of Freedom	Mean Square	F-Value	p-Value Probability > F
Model			710.81	9	78.98	64.84	<0.0001
Intercept	21.46	0.49		1
X1	−3.41	0.39	93.02	1	93.02	76.37	<0.0001
X2	−5.01	0.39	200.70	1	200.70	164.77	<0.0001
X3	1.94	0.39	29.99	1	29.99	24.62	0.0016
X1 X2	2.63	0.55	27.72	1	27.72	22.76	0.0020
X1 X3	−2.52	0.55	25.35	1	25.35	20.81	0.0026
X2 X3	1.35	0.55	7.24	1	7.24	5.94	0.0449
X12	7.08	0.54	211.03	1	211.03	173.25	<0.0001
X22	4.71	0.54	93.49	1	93.49	76.75	<0.0001
X32	−1.90	0.54	15.25	1	15.25	12.52	0.0095
Residual			8.53	7	1.22
Lack of fit			2.07	3	0.69	0.43	0.7440
Pure error			6.45	4	1.61
R2	0.9881		Adj R2	0.9729
C.V. %	4.23		Pred R2	0.9399
PRESS	43.25		Adeq Precision	33.461