3. A statistics teacher wants to investigate whether students from the north of a county and students from the south of the same county feel similarly stressed about examinations. The teacher carries out a psychometric test on 10 randomly selected students to give a score between 0 (low stress) and 100 (high stress) to measure their stress levels before a set of examinations. The results are shown in the table below.
| Student | Area | Stress Level |
| Heledd | North | 67 |
| Mair | North | 55 |
| Hywel | South | 26 |
| Gwyn | South | 70 |
| Liam | South | 36 |
| Marcin | South | 57 |
| Gosia | South | 32 |
| Kestutas | North | 64 |
| Erica | North | 60 |
| Tomos | North | 22 |
- State one reason why a Mann-Whitney test is appropriate.
- Conduct a Mann-Whitney test at a significance level as close to \(5 \%\) as possible. State your conclusion clearly.
- How could this investigation be improved?