A marine biologist measured the microplastic concentration (particles per litre) in water samples taken from two different locations: Location A (an offshore marine reserve) and Location B (a coastal estuary near an industrial zone). Ten samples of equal volume were collected from each location.
| Sample | Location A (Reserve) | Sample | Location B (Estuary) |
|---|---|---|---|
| 1 | 14 | 1 | 22 |
| 2 | 19 | 2 | 21 |
| 3 | 8 | 3 | 25 |
| 4 | 17 | 4 | 22 |
| 5 | 15 | 5 | 20 |
| 6 | 16 | 6 | 78 |
| 7 | 9 | 7 | 23 |
| 8 | 7 | 8 | 24 |
| 9 | 13 | 9 | 18 |
| 10 | 56 | 10 | 23 |
| Median | [ ] | Median | [ ] |
Complete Table 4 by calculating the median for the two locations. Why did the marine biologist use the median as a measure of central tendency rather than the mean?
235 exam-style questions on AQA A Level Psychology Data handling and analysis. Each one has a worked solution and a mark scheme showing where the marks go.