Trial No. | Coded variablesa | Uncoded variables | The forward extraction yield (%) | |||||||
A | B | C | D | A | B | C | D | Experimental | Predicted | |
1 | −1 | −1 | 0 | 0 | 33 | 5 | 0.015 | 2.1 | 65.23 | 64.81 |
2 | 1 | −1 | 0 | 0 | 45 | 5 | 0.015 | 2.1 | 69.2 | 68.64 |
3 | −1 | 1 | 0 | 0 | 33 | 5.8 | 0.015 | 2.1 | 75.5 | 76.05 |
4 | 1 | 1 | 0 | 0 | 45 | 5.8 | 0.015 | 2.1 | 72.58 | 72.99 |
5 | 0 | 0 | −1 | −1 | 39 | 5.4 | 0.01 | 1.9 | 76.1 | 76.34 |
6 | 0 | 0 | 1 | −1 | 39 | 5.4 | 0.02 | 1.9 | 73.24 | 72.52 |
7 | 0 | 0 | −1 | 1 | 39 | 5.4 | 0.01 | 2.3 | 70.9 | 71.61 |
8 | 0 | 0 | 1 | 1 | 39 | 5.4 | 0.02 | 2.3 | 72.1 | 71.85 |
9 | −1 | 0 | 0 | −1 | 33 | 5.4 | 0.015 | 1.9 | 72.28 | 73.84 |
10 | 1 | 0 | 0 | −1 | 45 | 5.4 | 0.015 | 1.9 | 66.23 | 69.71 |
11 | −1 | 0 | 0 | 1 | 33 | 5.4 | 0.015 | 2.3 | 70.23 | 66.63 |
12 | 1 | 0 | 0 | 1 | 45 | 5.4 | 0.015 | 2.3 | 73.21 | 71.53 |
13 | 0 | −1 | −1 | 0 | 39 | 5 | 0.01 | 2.1 | 71.22 | 71.72 |
14 | 0 | 1 | −1 | 0 | 39 | 5.8 | 0.01 | 2.1 | 79.23 | 76.62 |
15 | 0 | −1 | 1 | 0 | 39 | 5 | 0.02 | 2.1 | 64.55 | 67.03 |
16 | 0 | 1 | 1 | 0 | 39 | 5.8 | 0.02 | 2.1 | 78.36 | 77.73 |
17 | −1 | 0 | −1 | 0 | 33 | 5.4 | 0.01 | 2.1 | 69.5 | 70.97 |
18 | 1 | 0 | −1 | 0 | 45 | 5.4 | 0.01 | 2.1 | 74.23 | 73.92 |
19 | −1 | 0 | 1 | 0 | 33 | 5.4 | 0.02 | 2.1 | 71.3 | 71.75 |
20 | 1 | 0 | 1 | 0 | 45 | 5.4 | 0.02 | 2.1 | 70.89 | 69.56 |
21 | 0 | −1 | 0 | −1 | 39 | 5 | 0.015 | 1.9 | 78.3 | 74.96 |
22 | 0 | 1 | 0 | −1 | 39 | 5.8 | 0.015 | 1.9 | 73.25 | 72.04 |
23 | 0 | −1 | 0 | 1 | 39 | 5 | 0.015 | 2.3 | 60.2 | 61.55 |
24 | 0 | 1 | 0 | 1 | 39 | 5.8 | 0.015 | 2.3 | 76.58 | 80.06 |
25 | 0 | 0 | 0 | 0 | 39 | 5.4 | 0.015 | 2.1 | 80.2 | 82.24 |
26 | 0 | 0 | 0 | 0 | 39 | 5.4 | 0.015 | 2.1 | 82.56 | 82.24 |
27 | 0 | 0 | 0 | 0 | 39 | 5.4 | 0.015 | 2.1 | 83.26 | 82.24 |
28 | 0 | 0 | 0 | 0 | 39 | 5.4 | 0.015 | 2.1 | 82.9 | 82.24 |
29 | 0 | 0 | 0 | 0 | 39 | 5.4 | 0.015 | 2.1 | 82.3 | 82.24 |