A certain forum reported that in a survey of 2002 American adults, 22% said they believed in astrology.
(a)
Calculate a confidence interval at the 99% confidence level for the proportion of all adult Americans who believe in astrology. (Round your answers to three decimal places.)
,
Interpret the resulting interval.
We are 99% confident that the true population mean lies above this interval. We are 99% confident that this interval does not contain the true population mean. We are 99% confident that the true population mean lies below this interval. We are 99% confident that this interval contains the true population mean.
(b)
What sample size would be required for the width of a 99% CI to be at most 0.05 irrespective of the value of p̂? (Round your answer up to the nearest integer.)
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