The owner of a small convenience store is trying to decide whether to discontinue selling magazines. he suspects that only 5% of the customers buy magazines and thinks that he might be able to sell something more profitable. before making a final decision, he keeps track of the number of customers who buy magazines each day. on a typical day, he has 300 customers in his store. assuming this day was typical what would be the mean and standard deviation of the number of customers who buy magazines each day?