Researchers study two districts for three years. At the start, the districts have similar age distributions, average incomes and obesity rates. District J opens free exercise facilities and improves access to balanced food. District K makes neither change. The researchers measure the change in obesity rate in each district.
The researchers want to find out how much of any change in obesity rate in District J is due to the improved access to balanced food.
Which further district should be added to the study?
A district similar to J and K that opens free exercise facilities but does not change access to balanced food.
A younger district that opens free exercise facilities and improves access to balanced food.
A district similar to J and K that improves access to balanced food and starts a campaign to reduce alcohol intake.
A district with improved access to balanced food but a much higher average income.
102 exam-style questions on Edexcel GCSE Biology 5.4 Non-communicable diseases, covering 5.4.1 Interaction of factors in non-communicable disease, 5.4.2 Lifestyle factors and non-communicable disease, and 5.4.3 Treatments for cardiovascular disease. Each one has a worked solution and a mark scheme showing where the marks go.