statistics homework problem?
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 17 minutes and a standard deviation of 3 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 3% of its customers, how long should it make the guaranteed time limit (in minutes)?
- alexLv 72 months ago
P(X>20)=0.1586 ~ 16%
P(X<a)=97%=0.97 --->a = 22.65 minutes