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Interval estimates for proportions — Question 200

Original QCE Vault practice · 5 marks

Q200 · Practice questionTechnology-activeComplex unfamiliar5 marks

QUESTION 200 (5 marks)

A survey of 400400 people gives p^=0.58\hat p=0.58. Its approximate 95% confidence interval uses z=1.96z=1.96. A new survey is planned using the same planning value p=0.58p=0.58, but the new interval will have 99% confidence using z=2.576z=2.576. Determine the minimum sample size required so that the new 99% interval has margin of error no greater than the current 95% interval.
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