A lake contains five different types of fish. There are 1400 fish in total. John wishes to investigate the health of the fish in the lake. He decides to take a sample of 120 fish, consisting of 30 Roach, 24 Bream, 18 Rudd, 12 Tench and 36 Carp.
Give a reason why stratified random sampling cannot be used.
Find the estimated population of each type of fish.
59 exam-style questions on Edexcel A Level Maths Data Collection, covering 1.1 Populations and Samples, 1.2 Sampling, 1.3 Non-Random Sampling, 1.4 Types of Data, and 1.5 The Large Data Set. Each one has a worked solution and a mark scheme showing where the marks go.