Step 3
Add up the total of the n(n-1) column.
| Species observed | Number of individuals | |
| Field A (n) | n(n-1) | |
| Cocksfoot grass | 60 | 60 x (60-1) = 3540 |
| Timothy grass | 32 | 32 x (32-1) = 992 |
| Buttercup | 3 | 3 x (3-1) = 6 |
| Clover | 3 | 3 x (3-1) = 6 |
| Thistle | 1 | 1 x (1-1) = 0 |
| Dandelion | 7 | 7 x (7-1) = 42 |
| Total (N) | 106 | 4586 |