An anomaly is a data point that does not fit the general pattern or trend of the rest of the data.
Explain two possible reasons for the anomaly shown at X in Figure 1b.

| Distance downstream from source (km) | Mean bedload particle diameter (cm) |
|---|---|
| 2 | 45 |
| 5 | 36 |
| 8 (Point X) | 62 |
| 11 | 24 |
| 14 | 15 |