Confidence of being correct

Reference no: EM13104483

An advertising agency that serves a major radio station wants estimate the mean amount of time that the station's audience spends listening to the radio daily. From studies, the standard deviation is estimated as 45 minutes. what sample size is need if the agency wants to be 90% confidence of being correct to within +/- 5 minutes? if 90% is desired, how many listeners need to be selected?

Reference no: EM13104483

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