A sports centre asks only people leaving a weekday yoga class whether the centre should buy more yoga equipment.
Explain why the resulting sample is likely to be biased.
Suggest a sampling frame and a sampling method that would produce a more representative sample of centre users.
36 exam-style questions on OCR (MEI) A Level Maths 2.1 Sampling, covering 2.1.1 Population and sample, 2.1.2 Samples to make informal inferences, 2.1.3 Random sampling, 2.1.4 Variety of sampling techniques, 2.1.5 Select or evaluate sampling techniques, and 2.1 Sampling. Each one has a worked solution and a mark scheme showing where the marks go.