Table 5.

Regression results of the CCD

Factor	Coefficient estimate	F-value	Prob > F	Significance
Intercept	211.23
Model		71.36	<0.0001	Significant
A	−2.25	1.20	0.2911
B	−4.3	4.39	0.0536
C	2.4	1.34	0.2643
D	2.9	2.06	0.1718
AB	−2.41	0.92	0.3529
AC	1.05	0.18	0.6811
AD	0.79	0.098	0.7581
BC	−2.17	0.74	0.4024
BD	−5.2	4.26	0.0567
CD	−5.44	4.69	0.0469
A2	−34.2	316.76	<0.0001
B2	−37.99	391.87	<0.0001
C2	−36.5	360.97	<0.0001
D2	−34.74	327.56	<0.0001

*Lack of Fit = 4.69, Coefficient of Variation (%) = 10.41, R² = 0.9852, Adj R-Squared = 0.9714, Pred R-Squared = 0.9210