An advertising agency that serves a major radio station wants toestimate the mean amount of time that the station's audience spendslistening to the radio daily. From past studies, the standarddeviation is estimated as 48 minutes. A. What sample size is neededif the agency wants to be 95% confident of being correct to within+/-5 minutes? A sample size of ____ listeners is needed. ( Round upto the nearest integer.) B. If 99% confidence is desired, how manylisteners need to be selected? If 99% confidence is desired,___listeners need to be selected. (Round up to the nearestinteger.)
