Factor | Symbol | −1 | 0 | +1 | −1.68 | +1.68 |
Temperature (˚C) | X1 | 30 | 40 | 50 | 23 | 56.8 |
Time (days) | X2 | 3 | 6 | 9 | 1 | 11 |
pH | X3 | 4 | 6 | 8 | 2.6 | 9.3 |
No of core points nj | 8 |
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No of starlike points nα | 6 | |||||
No of null points no | 6 | |||||
Total no of points n | 20 |