A psychologist conducted an investigation into whether the use of blue-light filtering software on smartphones before bedtime affects self-reported sleep quality. Two groups of participants were studied over a two-week period: Group A used a blue-light filter on their devices after 9:00 PM, while Group B used no screen filters.
At the end of the study, participants rated their overall sleep quality on a scale from 1 (very poor sleep) to 10 (excellent sleep).
Table 1: Frequency of sleep quality ratings for Group A (with filter) and Group B (without filter)
| Sleep Quality Rating | Frequency (Group A: Filter) | Frequency (Group B: No Filter) |
|---|---|---|
| 1 | 0 | 2 |
| 2 | 1 | 4 |
| 3 | 2 | 6 |
| 4 | 3 | 9 |
| 5 | 7 | 11 |
| 6 | 11 | 5 |
| 7 | 8 | 2 |
| 8 | 5 | 1 |
| 9 | 2 | 0 |
| 10 | 1 | 0 |
| Median | 6 | 4 |
| Range | 8 | 7 |
Draw a line graph to show the distribution of the frequency of sleep quality ratings for Group B (the group with no screen filters).
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.