A cognitive psychologist investigated the relationship between nightly sleep duration and cognitive processing speed. They measured the average sleep duration (in hours) over a week and collected scores on a timed digit-symbol substitution task (ranging from 1 to 100) for a group of 8 participants.
Complete Table 1 and calculate Spearman's rank correlation coefficient (rsr_srs) between sleep duration and cognitive processing scores.
Table 1: Sleep duration and cognitive scores with partial ranks
| Sleep duration (hours) | Rank 1 | Cognitive score | Rank 2 | Difference (ddd) | Difference squared (d2d^2d2) |
|---|---|---|---|---|---|
| 8.2 | 8 | 75 | 6 | ||
| 7.5 | 7 | 90 | 8 | ||
| 7.0 | 6 | 85 | 7 | ||
| 6.4 | 5 | 68 | 5 | ||
| 5.8 | 3.5 | 52 | 3 | ||
| 5.8 | 3.5 | 58 | 4 | ||
| 5.0 | 2 | 45 | 2 | ||
| 4.2 | 1 | 30 | 1 | ||
| Total: |
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 638 questions, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
