| Assay | variables | |||
| Coded | Decoded | |||
| Hot water (˚C) | Calcium chloride (%) | X1 (˚C) | X2 (%) | |
| 1 | −1 | −1 | 50 | 2 |
| 2 | 1 | −1 | 60 | 2 |
| 3 | −1 | 1 | 50 | 4 |
| 4 | 1 | 1 | 60 | 4 |
| 5 | −1.41 | 0 | 47.95 | 3 |
| 6 | 1.41 | 0 | 62.05 | 3 |
| 7 | 0 | −1.41 | 55 | 0.88 |
| 8 | 0 | 1.41 | 55 | 5.12 |
| 9 | 0 | 0 | 55 | 3 |
| 10 | 0 | 0 | 55 | 3 |
| 11 | 0 | 0 | 55 | 3 |
| 12 | 0 | 0 | 55 | 3 |