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 1515 minutes and a standard deviation of 3.53.5 minutes.
​(a) The automotive center guarantees customers that the service will take no longer than 2020 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 55​% of its​ customers, how long should it make the guaranteed time​ limit?

Answer 1

I thinkit is b because we arent tht fast