A school posts a questionnaire about homework on its social-media page. During the next 24 hours, 96 pupils choose to reply.
Give two reasons why these replies may not represent all pupils at the school.
Suggest a more suitable sampling method and explain one improvement it would provide.
36 exam-style questions on CCEA A Level Maths 2.4 Statistical sampling, covering 2.4.1 Statistical sampling, 2.4.2 Statistical sampling, 2.4.3 Statistical sampling, and 2.4.4 Statistical sampling. Each one has a worked solution and a mark scheme showing where the marks go.