Question

The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal​ distribution, with a mean of 19 minutes and a standard deviation of 3.5 minutes.

​(a) The automotive center guarantees customers that the service will take no longer than 20 minutes. If 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 4​% of its​ customers, how long should it make the guaranteed time​ limit?

Answer 1

a. 38.97% Customer receive service for half price.

b. If company doesn't want to give discount to more than 4% of its customers, then company should make guaranteed time limit to 25.125 minutes

Complete solution is given in attached image:

Thank You.