A health team studied polio in four districts for 24 weeks.
The table shows the percentage of children vaccinated against polio and the number of weeks in which no new cases were recorded.
| District | Children vaccinated (%) | Weeks with no new cases |
|---|---|---|
| L | 52 | 4 |
| M | 68 | 9 |
| N | 84 | 16 |
| O | 95 | 23 |
Which conclusion about the districts is supported by the data?
District O recorded no new cases of polio at any time during the study
Each rise in vaccination produced the same rise in the number of case-free weeks
Districts with a higher percentage vaccinated had more weeks with no new cases
Districts with a higher percentage vaccinated had fewer weeks with no new cases
252 exam-style questions on AQA GCSE Biology 3.1 Communicable diseases, covering 3.1.1 Communicable (infectious) diseases, 3.1.2 Viral diseases, 3.1.3 Bacterial diseases, 3.1.4 Fungal diseases, 3.1.5 Protist diseases, 3.1.6 Human defence systems, 3.1.7 Vaccination, 3.1.8 Antibiotics and painkillers, and 3.1.9 Discovery and development of drugs. Each one has a worked solution and a mark scheme showing where the marks go.