Table 2.

Variance analysis of items in regression equation.

Sources of Variation	Sum of Squares	df	Mean Square	F value	P value
model	8.02	9	0.89	14.98	0.0009
X1	0.026	1	0.026	0.44	0.5263
X2	0.43	1	0.43	7.19	0.0315
X3	0.00513	1	0.005513	0.093	0.7697
X1X2	0.11	1	0.11	1.89	0.2120
X1X3	0.00202	1	0.00202	0.034	0.8589
X2X3	1.12	1	1.12	18.89	0.0034
X12	2.80	1	2.80	47.13	0.0002
X22	1.11	1	1.11	18.66	0.0035
X32	1.77	1	1.77	29.77	0.0009
residual	0.42	7	0.059
lack of fit	0.39	3	0.13	20.12	0.0071
pure error	0.026	4	0.00647
total	8.43	16
R2	0.9506
Radj2	0.8872
Adeq precision	10.141