Table 4.

Model equations for Y_S, Y_Y, Y_C*, Y_h* and Y_F responses.

Model	Polynomial Equation 1
	Coded Value of Factors	Actual Value of Factors
1	${\mathrm{Y}}_{\mathrm{S}}=55.7-66.8{\mathrm{X}}_1-43.3{\mathrm{X}}_2+11.88{\mathrm{X}}_1^2+11.82{\mathrm{X}}_2^2$ (2)	${\mathrm{Y}}_{\mathrm{S}}=1199-1857{\mathrm{X}}_1-3230{\mathrm{X}}_2+1188{\mathrm{X}}_1^2+4727{\mathrm{X}}_2^2$ (3)
2	${\mathrm{Y}}_{\mathrm{Y}}=4.9022+0.0094{\mathrm{X}}_2-0.0051{\mathrm{X}}_3-0.01521{\mathrm{X}}_2^2-0.00738{\mathrm{X}}_3^2$ (4)	${\mathrm{Y}}_{\mathrm{Y}}=4.316+3.229{\mathrm{X}}_2+1.375{\mathrm{X}}_3-6.08{\mathrm{X}}_2^2-2.95{\mathrm{X}}_3^2$ (5)
3	${\mathrm{Y}}_{\mathrm{C}*}=14.672+0.2139{\mathrm{X}}_1+0.2947{\mathrm{X}}_4+0.039{\mathrm{X}}_4^2$ (6)	${\mathrm{Y}}_{\mathrm{C}*}=13.204+2.139{\mathrm{X}}_1-0.136{\mathrm{X}}_4+0.0295{\mathrm{X}}_4^2$ (7)
4	${\mathrm{Y}}_{\mathrm{h}*}=73.29+0.2455{\mathrm{X}}_1-0.2005{\mathrm{X}}_3+0.1261{\mathrm{X}}_4+0.0675{\mathrm{X}}_4^2-0.499{\mathrm{X}}_1{\mathrm{X}}_4$ (8)	${\mathrm{Y}}_{\mathrm{h}*}=60.18+31.3{\mathrm{X}}_1-4.01{\mathrm{X}}_3+1.599{\mathrm{X}}_4+0.051{\mathrm{X}}_4^2-4.34{\mathrm{X}}_1{\mathrm{X}}_4$ (9)
5	${\mathrm{Y}}_{\mathrm{F}}=4.1219+0.0682{\mathrm{X}}_1-0.0305{\mathrm{X}}_2+0.0113{\mathrm{X}}_3-0.004{\mathrm{X}}_4+0.0314{\mathrm{X}}_3^2-0.242{\mathrm{X}}_1{\mathrm{X}}_4+0.267{\mathrm{X}}_2{\mathrm{X}}_3+0.325{\mathrm{X}}_2{\mathrm{X}}_4-0.391{\mathrm{X}}_3{\mathrm{X}}_4$ (10)	${\mathrm{Y}}_{\mathrm{F}}=2.46+14.67{\mathrm{X}}_1-64.9{\mathrm{X}}_2+12.5{\mathrm{X}}_3+1.336{\mathrm{X}}_4+12.56{\mathrm{X}}_3^2-2.103{\mathrm{X}}_1{\mathrm{X}}_4+106.9{\mathrm{X}}_2{\mathrm{X}}_3+5.66{\mathrm{X}}_2{\mathrm{X}}_4-6.81{\mathrm{X}}_3{\mathrm{X}}_4$ (11)

¹ X₁, X₂ and X₃ factors are presented in Table 1.