An ecologist investigated the abundance of encrusting lichen on a rocky coastal cliff. They estimated the percentage cover of the lichen using a quadrat divided into 20 equal squares. If a square contains any part of the lichen, it is counted.
The table below shows the results of their investigation:
| Quadrat number | Number of squares containing lichen | Percentage cover of lichen (%) |
|---|---|---|
| 1 | 13 | 65 |
| 2 | 9 | 45 |
| 3 | 16 | 80 |
| 4 | 11 | 55 |
| 5 | 15 | PPP |
| 6 | 8 | 40 |
Calculate the percentage cover PPP for Quadrat 5 and the mean percentage cover MMM for all six quadrats.