you have been assigned the task of conducting a survey to study prescription medication purchases of adults. a) if you want to estimate the percentage of adults who have purchased prescription...

you have been assigned the task of conducting a survey to study prescription medication purchases of adults.

a) if you want to estimate the percentage of adults who have purchased prescription medication during the past 30 days, how many adults must you survey if you want 95% confidence that your percentage has a margin of error of these percentage points?

b)if you want to estimate the mean amount that adults have spent on prescription medications during the past 30 days, how many adults must you survey if you want 95% confidence that your sample mean is in error by no more than $5? (based on results from a pilot study, assume that the standard deviation interval estimate of the mean amounts spent on prescription medications in the past 30 days is $39)

C) if you plan to obtain the estimates described in parts (a) and (b) with a single survey having several questions, how many adults must be surveyed?