A college wants to estimate the proportion of its students who travel by public transport. It has 640 full-time students and 160 part-time students.
One researcher proposes asking 80 volunteers. Another proposes selecting a stratified random sample of 80 students, using study mode as the stratum.
Calculate the numbers of full-time and part-time students in the stratified sample.
Explain two reasons why the stratified random sample is preferable to the volunteer sample.
State why the result from the stratified sample is still an estimate rather than the exact population proportion.
8 exam-style questions on CCEA A Level Maths 2.4.3 Statistical sampling. Each one has a worked solution and a mark scheme showing where the marks go.