A cognitive psychologist conducted a study to investigate the relationship between nightly sleep duration and cognitive performance the following morning. The data collected from 12 participants is shown in the table below.
| Participant | Nightly sleep duration (minutes) | Cognitive performance score (1–100) | Rank: Nightly sleep | Rank: Cognitive performance |
|---|---|---|---|---|
| A | 420 | 78 | 7 | 8 |
| B | 480 | 85 | 9 | 10 |
| C | 300 | 52 | 3 | 3 |
| D | 360 | 64 | 5 | 5 |
| E | 270 | 45 | 2 | 2 |
| F | 450 | 81 | 8 | 9 |
| G | 540 | 92 | 11 | 11 |
| H | 330 | 58 | 4 | 4 |
| I | 240 | 38 | 1 | 1 |
| J | 390 | 70 | 6 | 6 |
| K | 570 | 95 | 12 | 12 |
| L | 510 | 72 | 10 | 7 |
Explain why it is more appropriate to use the mean, rather than the median, to calculate the central tendency for the cognitive performance scores in this study.
513 exam-style questions on OCR A Level Psychology Data recording, analysis and presentation. Each one has a worked solution and a mark scheme showing where the marks go.