Table 7.

Coded and un-coded values of the variables.

Variables (%)	Un-Coded	Coded
Gly concentration	0.55	−1
	0.65	0
	0.75	1
dl-Thr concentration	0.6	−1
	1	0
	1.5	1
Tween 80 concentration	0.02	−1
	0.06	0
	0.1	1