A reservoir contains five different types of fish.
There are an estimated 300 Perch, 240 Trout, 180 Chub, 120 Dace and 360 Carp.
Aisha wishes to investigate the health of the fish in the reservoir.
She decides to take a sample of 100 fish.
Give a reason why stratified random sampling cannot be used.
Explain how a sample of size 100 could be taken to ensure that the estimated populations of each type of fish are fairly represented.
You should state the name of the sampling method used.
14 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.