A health-data file contains an impossible age, two identical patient rows, several #N/A blood-pressure values and one very large but possible weight.
Describe an appropriate action for each of the four features.
Explain why replacing all unusual or unavailable values by the corresponding sample mean is poor practice.
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.