Question: A public health official is charged with completing an annual survey of a county population, checking for incidents of a certain viral infection over the past year.
(a) Suppose she wants a 99% confidence level in the results of the survey with an error of no more than 3%. How many people should she survey?
(b) How many people should she survey if, in (a), she is willing to settle for a 95% confidence level?
(c) Suppose, in the previous year's study, it was found that, p¯ = 0.12. Make an estimate of how many people she should survey for a 99% confidence level and an error of no more than 2%.