A library selects a random starting member from the first 20 names on an alphabetical list and then selects every 20th member until 30 members have been chosen.
State the sampling technique used.
Give one advantage and one possible disadvantage of this technique.
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.