Study Figure 3a, which shows sediment size data collected by a group of GCSE students at length intervals along a river channel.
| Site | Mean sediment size (mm) |
|---|---|
| 1 | 44.3 |
| 2 | 36.8 |
| 3 | 29.5 |
| 4 | 21.1 |
| 5 | 14.4 |
Calculate the mean sediment size for the five sites shown in Figure 3a.
Give your answer to one decimal place. You must show your workings.
