An extract from the AQA Large Data Set contains records for 1400 cars, each of which is either diesel or petrol.
Sofia takes a sample from this extract in which the numbers of diesel and petrol cars are in the same proportions as in the extract. Her sample contains 18 diesel cars and 42 petrol cars.
Write down the size of Sofia's sample.
Calculate the number of diesel cars in the extract of 1400 cars.
State one assumption you have made in answering part (b).
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.