Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
Anita conducted a survey of 140 students chosen at random from her college. She found that 49 of those students watched a TV programme called Bunch.
(a)[3]
Calculate an approximate 98% confidence interval for the proportion, $p$, of students at Anita’s college that watch Bunch.
(b)[1]
Without doing any calculation, briefly explain how Carlos can use Anita’s survey results to find a narrower confidence interval for $p$.
Worked solution & mark scheme
This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Confidence interval formula written in the correct form, for example $0.35 \pm z\sqrt{\frac{0.35(1-0.35)}{140}}$” …