The OCR large data set contains travel-to-work data for 348 Local Authorities in England and Wales in 2001 and 2011. A researcher wants to estimate how the proportion of employed people who worked mainly at or from home changed between the two census years.
In this question you must show detailed reasoning.
Define the two proportions that should be calculated for each selected Local Authority.
One researcher proposes a simple random sample of Local Authorities. Another proposes stratifying by region. Give one advantage of each proposal.
State four features of the data or method that must be considered when interpreting the result.
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.