Symbol
Factor
Coded levels of variables
-1.00
0
1.00
A
Crude oil concentration (heavy and light%(w/v)
0.25
0.5
1
B
Solid waste date concentration% (w/v)
0.2
0.4
0.8
C
Incubation period (days)
7
14
28
Table 1:
Coded and actual values of variables.
