Suppose the wait time for license renewal at the local office of state motor vehicle department has been found to be normally distributed with a mean of 30 minutes and standard deviation of 8 minutes. suppose that in an effort to provide better service to the public, the director of the local office is permitted to provide discounts to those individuals waiting time exceeding a predetermined time. the director decides that 15% of the customers should receive this discount.
what number of minutes do they receive the discount?