A researcher records the journey time to work, in minutes, for six people as
24, 31, −18, 27, missing, 24024,\ 31,\ -18,\ 27,\ \text{missing},\ 24024, 31, −18, 27, missing, 240.
Identify two entries that should be investigated before the data are analysed, giving a reason for each.
State one appropriate way to deal with the missing value.
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.