Mathematics 9709 · AS & A Level · Sampling and estimation

Sampling and estimation — practice question

In a particular country, the chance that a child owns a bicycle is $0.65$.
(i)[3]

A random sample of $15$ children from this country is selected. Find the probability that more than $12$ own a bicycle.

(ii)[4]

A random sample of $250$ children from this country is selected. Use a suitable approximation to find the probability that fewer than $179$ own a bicycle.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Recognises $P(X>12)=P(X=13,14,15)$ from the binomial structure

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