Two students are discussing sampling.
Ravi says: "If I keep increasing the size of an opportunity sample, my estimate will get as close as I like to the population value."
Sian says: "A simple random sample of 20 is always better than an opportunity sample of 2000."
Explain why Ravi's statement is wrong. Your answer should refer to both bias and sampling variation.
Comment on Sian's statement.
28 exam-style questions on AQA A Level Maths 2.1 K: Statistical sampling, covering 2.1.1 Populations, samples and sampling techniques. Each one has a worked solution and a mark scheme showing where the marks go.