Dr Aris conducted a correlational study to investigate the relationship between daily screen time before bed (hours) and subjective sleep quality rating (on a scale of 1 to 10, where 10 is excellent sleep).
The results from Dr Aris's investigation are shown in Table 1.
Complete Table 1 and calculate the Spearman's rank correlation coefficient for Dr Aris's investigation.
Table 1: Daily screen time and sleep quality ratings
| Screen time before bed (hours) | Rank 1 | Subjective sleep quality rating | Rank 2 | ddd | d2d^2d2 |
|---|---|---|---|---|---|
| 3.5 | 4.5 | 5 | 4 | ||
| 1.0 | 2 | 8 | 6 | ||
| 3.5 | 4.5 | 4 | 3 | ||
| 4.5 | 6 | 3 | 2 | ||
| 0.5 | 1 | 9 | 7 | ||
| 5.0 | 7 | 2 | 1 | ||
| 2.0 | 3 | 7 | 5 | ||
| Total: | ∑d2=\sum d^2 =∑d2= |
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.