A developmental psychologist wants to investigate study habits using a stratified sample of 80 students from a secondary school. The school has 450 students in Key Stage 4 and 350 students in Key Stage 5.
Calculate the number of Key Stage 4 students that should be selected for this stratified sample.
353535
404040
454545
565656
644 exam-style questions on OCR A Level Psychology Research methods and techniques. Each one has a worked solution and a mark scheme showing where the marks go.