Design point Independent variables
X1                                X2
Variables in their natural form
X1   (%)                          X2   (°C)
1 1 1 20 100
2 1 2 20 120
3 1 3 20 130
4 2 1 25 100
5 2 2 25 120
6 2 3 25 130
7 3 1 30 100
8 3 2 30 120
9 3 3 30 130
X1= Feed Moisture, X2= Barrel Temperature
Table 2: Experimental layout with the Coded and Natural values