Table 2.

ANOVA for dependent variable: the yield of RAMP.

Source	Sum of Squares	df	Mean Square	F	Sig. (Prob > F)
Corrected model	100.64	14	7.19	1337.56	<0.0001
X1	5.20	1	5.20	967.75	<0.0001
X2	19.28	1	19.28	3587.29	<0.0001
X3	25.03	1	25.03	4656.98	<0.0001
X4	18.80	1	18.80	3498.22	<0.0001
X1X2	<0.0001	1	<0.0001	0.91	0.3558
X1X3	0.61	1	0.61	113.21	<0.0001
X1X4	0.12	1	0.12	21.51	0.0004
X2X3	0.43	1	0.43	79.83	<0.0001
X2X4	0.10	1	0.10	19.05	0.0006
X3X4	0.28	1	0.28	52.27	<0.0001
X12	11.03	1	11.03	2052.10	<0.0001
X22	14.07	1	14.07	2617.62	<0.0001
X32	11.56	1	11.56	2151.64	<0.0001
X42	11.50	1	11.50	2139.57	<0.0001
Residual	0.075	14	<0.0001
Lack of fit	0.057	10	<0.0001	1.25	0.4493
Pure error	0.018	4	<0.0001
Cor total	100.71	28
R2	0.9993	SD	0.60
R2adj	0.9985	C.V.%	0.68
Adeq precision	110.900