4. A company selects a random sample of five of its warehouses. The table below summarises the number of employees, in thousands, at each warehouse and the number of reported first aid incidents at each warehouse during 2017
| Warehouse | A | \(B\) | C | D | E |
| Number of employees, (in thousands) | 2 | 1 | 3.8 | 3 | 2.2 |
| Number of reported first aid incidents | 15 | 10 | 40 | 26 | 23 |
The personnel manager claims that the mean number of reported first aid incidents per 1000 employees is the same at each of the company's warehouses.
- Stating your hypotheses clearly, use a \(5 \%\) level of significance to test the manager's claim.
Jean, the safety officer at warehouse \(C\), kept a record of each reported first aid incident at warehouse \(C\) in 2017. Jean wishes to select a systematic sample of 10 records from warehouse \(C\).
- Explain, in detail, how Jean should obtain such a sample.