A Researcher Wishes To? Estimate, With 99?% ?Confidence, The Population Proportion Of Adults Who Say Chocolate
A researcher wishes to? estimate, with 99?% ?confidence, the population proportion of adults who say chocolate is their favorite ice cream flavor. Her estimate must be accurate within 4?% of the population proportion.
(a) What is the minimum sample size needed assuming that no prior information is? available?
?(b) Find the minimum sample size? needed, using a prior study that found that 20?% of the respondents said their favorite flavor of ice cream is chocolate.
?(c) Compare the results from parts? (a) and? (b).