Table 2.

Analysis of Variance (ANOVA), factors, and their interaction effects.

Source	Sum of Squares	df	Mean Square	F-Value	p-Value
Model	5213.5733	14	372.3981	89.90	<0.0001
X1-Amplitude	96.1200	1	96.1200	23.20	0.0002
X2-Extraction Time	341.4867	1	341.4867	82.44	<0.0001
X3-Solvent: solid	1314.6840	1	1314.6840	317.38	<0.0001
X4-Temperature	2950.1620	1	2950.1620	712.20	<0.0001
X1X2	5.7002	1	5.7002	1.38	0.2591
X1X3	22.1606	1	22.1606	5.35	0.0353
X1X4	27.3268	1	27.3268	6.60	0.0214
X2X3	1.0868	1	1.0868	0.26	0.6160
X2X4	13.4873	1	13.4873	3.26	0.0913
X3X4	129.6752	1	129.6752	31.30	<0.0001
$X_1^2$	1.6450	1	1.6450	0.40	0.5381
$X_2^2$	0.0073	1	0.0073	0.00	0.9670
$X_3^2$	1.3113	1	1.3113	0.32	0.5820
$X_4^2$	303.2210	1	303.2210	73.20	<0.0001
Residual	62.1349	15	4.1423
Lack of Fit	54.8974	10	5.4897	3.79	0.0771
Pure Error	7.2375	5	1.4475
Cor Total	5275.7082	29
R2	0.9882
Adjusted R2	0.9772
Predicted R2	0.9381
Adeq. Precision	37.40
Mean	90.7793
C.V. %	2.2420