o The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal distribution, with a means of 19 minutes and a standard deviation of 2 minutes (a) The automotive center guarantees customers that the service will take no longer than 20 minutes. It does take longer, the customer will receive the service for half-price. What percent of customers receive the service for half price? (b) If the automotive center does not want to give the discount to more than 5% of its customers, how long should it make tho guaranteed time limit? Click the icon to view a table of areas under the normal curve (a) The percent of customers that receive the service for all price is % (Round to two decimal places as needed) (b) The guaranteed time imtis minutes. (Round up to the nearest Tumute.)