The Headteacher of a school is thinking about making changes to the school day. She wants to take a sample of 60 students so that she can find out what the students think about the proposed changes. The names of the 1200 students of the school are listed alphabetically. Explain why systematic sampling is likely to be quicker than simple random sampling in this situation. (1) (ii) With reference to this situation, - explain why systematic sampling may introduce bias compared to simple random sampling - give an example of the bias that may occur when using this alphabetical list (2) When the Headteacher completes the systematic sample of size 60 she finds that 6 students were to be selected from Year 9. The Head of Mathematics suggests that a stratified sample of size 60 would be a more appropriate method. There were 200 students in Year 9.

Answer:

Knowledge points:

Solution: