A psychologist investigated the relationship between physiological stress and subjective state anxiety. They measured salivary cortisol levels (μ \mu\,μg/dL) and collected self-reported state anxiety scores (from 1 to 50) for a group of 8 participants.
Complete Table 1 and calculate Spearman's rank correlation coefficient (rsr_srs) between salivary cortisol levels and anxiety scores.
Table 1: Cortisol levels and anxiety scores with partial ranks
| Salivary cortisol (μ \mu\,μg/dL) | Rank 1 | Anxiety score | Rank 2 | Difference (ddd) | Difference squared (d2d^2d2) |
|---|---|---|---|---|---|
| 0.92 | 8 | 45 | 7 | ||
| 0.81 | 7 | 38 | 5 | ||
| 0.74 | 6 | 48 | 8 | ||
| 0.65 | 5 | 31 | 4 | ||
| 0.52 | 3.5 | 42 | 6 | ||
| 0.52 | 3.5 | 24 | 2 | ||
| 0.41 | 2 | 27 | 3 | ||
| 0.28 | 1 | 15 | 1 | ||
| Total: |
638 exam-style questions on Edexcel A Level Psychology Methods. Each one has a worked solution and a mark scheme showing where the marks go.