Table 3.

Regression results for FRAP and TPC (coded quadratic models): combined coefficient table.

Response	Term	Coef	SE Coef	t	P-value	VIF
FRAP	Constant	10.8633	0.0727	149.40	0.000
	X1	−0.2169	0.0912	−2.38	0.039	1.00
	X 2	−1.5660	0.0912	−17.18	0.000	1.00
	X3	−0.5595	0.0912	−6.14	0.000	1.00
	X12	1.4590	0.1450	10.03	0.000	1.08
	X 2 2	−0.9830	0.1450	−6.76	0.000	1.08
	X32	−1.3040	0.1450	−8.97	0.000	1.08
	X1 × X2	−1.2310	0.2580	−4.77	0.001	1.00
	X1 × X3	1.2560	0.2580	4.87	0.001	1.00
	X2 × X3	0.3490	0.2580	1.35	0.205	1.00
TPC	Constant	139.6680	0.6440	216.99	0.000
	X1	−0.9450	0.8070	−1.17	0.269	1.00
	X 2	−14.6460	0.8070	−18.15	0.000	1.00
	X3	−8.0260	0.8070	−9.95	0.000	1.00
	X12	−5.1100	1.2900	−3.97	0.003	1.08
	X 2 2	−30.0300	1.2900	−23.33	0.000	1.08
	X32	−34.7300	1.2900	−26.98	0.000	1.08
	X1 × X2	−16.1900	2.2800	−7.09	0.000	1.00
	X1 × X3	45.6100	2.2800	19.99	0.000	1.00
	X2 × X3	7.5000	2.2800	3.28	0.008	1.00

Coef, regression coefficient (coded units); t, t-statistic; SE, standard error; VIF, variance inflation factor.

Terms: X1, X₂, X3 represent coded factors; X?² indicates quadratic terms; X? × X? indicates interaction terms.