QCEVault

Interval estimates for proportions — Question 100

Original QCE Vault practice · 7 marks

Q100 · Practice questionTechnology-activeComplex unfamiliar7 marks

QUESTION 100 (7 marks)

In a survey of 800800 people, 456456 support a proposal. (a) Using z=2.576z=2.576, construct an approximate 99% confidence interval for the population proportion. (b) A new survey will use a 95% confidence interval and the same planning estimate of the proportion. Determine the minimum sample size needed so that its margin of error is at most half the margin from part (a).
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