A researcher wishes to​ estimate, with 95 ​% ​confidence, the population proportion of adults who eat fast food four to six times per week. Her estimate must be accurate within 1​% of the population proportion. ​(a) No preliminary estimate is available. Find the minimum sample size needed.

​(b) Find the minimum sample size​ needed, using a prior study that found that ​28% of the respondents said they eat fast food four to six times per week.

​(a) What is the minimum sample size needed assuming that no prior information is​ available?

n=

​(Round up to the nearest whole number as​ needed.)

​(​b) What is the minimum sample size needed using a prior study that found that 28​% of the respondents said they eat fast food four to six times per​ week?

n=

​(Round up to the nearest whole number as ​needed.)