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Determine $\alpha$ correct to the nearest integer.
Mathematics 9709 · AS & A Level · Continuous random variables
Continuous random variables — practice question
A student wants to estimate the proportion, $p$, of students at her college who have exactly one brother. She takes a random sample of 50 students at her college and discovers that 18 of them have exactly one brother. She then works out an approximate $\alpha\%$ confidence interval for $p$ and finds that the lower boundary of the interval is $0.244$ correct to 3 significant figures.
Worked solution & mark scheme
This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Apply the correct equation $\dfrac{18}{50}=z\sqrt{\dfrac{18\times(1-18/50)}{50}}$ or a mathematically equivalent standardisation.” …
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