You are in charge of selling advertising for radio station WQAA. The fee you can set for airtime is directly related to the share of the listening market your station reaches. From time to time, you conduct surveys to determine WQAA's share of the market. This month, when you contacted 200 randomly selected residential phone numbers, 12 respondents said they listen to WQAA.
How large a sample size will need to be selected if we wish to be 99% confident of being within 2% of the actual population percentage of the market who are WQAA listeners?