A council invites residents to complete an online survey about a proposed cycle lane. Of 1250 responses, 78% support the proposal. There are 96,000 adult residents in the council area.
Identify the sampling technique.
Estimate the number of adult residents who support the proposal if the sample proportion is used.
Give three reasons why this estimate may be unreliable.
36 exam-style questions on OCR A Level Maths 2.1 Statistical Sampling, covering 2.1.1 Population and sample, 2.1.2 Informal inferences from samples, 2.1.3 Sampling techniques, 2.1.4 Selecting or critiquing sampling techniques, and 2.1 Statistical Sampling. Each one has a worked solution and a mark scheme showing where the marks go.