Two students each want a sample of 40 cars from a garage's numbered list of 1000 cars, in order to estimate the mean CO emission of the cars on the list.
Ada generates 40 different random integers between 1 and 1000 and takes the cars with those numbers.
Ben takes the 40 cars whose owners replied first to an email asking for volunteers.
State which student's method is more likely to produce a representative sample, and justify your answer by reference to both methods.
Ben says his sample is better because it was much quicker to obtain. Comment on Ben's claim.
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.