Table 2.

Analysis of variance (ANOVA) for COY % and DPPH %

Source	COY (%)			DPPH (%)
	Sum of squares	Coefficient	P value Prob > F	Sum of squares	Coefficient	P value Prob > F
Model	1320.81	29.49	< 0.0001HS	1405.78	70.73	< 0.0001HS
X1-sample-solvent ratio	305.045	4.12	< 0.0001HS	188.43	3.24	< 0.0001HS
X2-amplitude level	26.25	1.21	< 0.0001HS	17.306	0.98	< 0.0001HS
X3-temperature	0.0566	0.056	0.7311	0.493	− 0.17	0.1150
X4-time	1.306	− 0.27	0.1134	2.645	− 0.38	0.0015S
X1X2	5.37	0.58	0.0039S	5.65	0.59	< 0.0001HS
X1X3	2.665	− 0.41	0.0298S	7.65	− 0.69	< 0.0001HS
X1X4	40.35	− 1.59	< 0.0001HS	10.44	− 0.81	< 0.0001HS
X2X3	2.095	− 0.36	0.0500S	1.749	− 0.33	0.0066S
X2X4	42.08	− 1.62	< 0.0001HS	20.22	− 1.12	< 0.0001HS
X3X4	0.0315	− 0.044	0.7976	4.441	0.53	0.0002S
X21	54.05	− 4.57	< 0.0001HS	10.68	− 2.03	< 0.0001HS
X22	29.91	− 3.40	< 0.0001HS	63.38	− 4.95	< 0.0001HS
X23	10.08	− 1.97	0.0003S	21.35	− 2.87	< 0.0001HS
X24	16.75	− 2.54	< 0.0001HS	47.26	− 4.27	< 0.0001HS
Residual	6.936			2.64
Lack of fit	4.976		0.4183	2.14		0.207
SD		0.68		SD		0.42
CV %		3.09		CV %		0.67
R2		0.9948		R2		0.9981
Adj R2		0.9899		Adj R2		0.9964
Pred R2		0.9758		Pred R2		0.9877
Adeq. pre		43.75		Adeq. pre		70.15

HS highly significant, S significant