The mean time from prescription dropoff to medicine pickup f

The mean time from prescription drop-off to medicine pickup for a customer served at Heisenbergs Pharmacy is 51 minutes, with a standard deviation of 17 minutes. Assuming a normal distribution, what is the probability that a randomly chosen customer experiences service done between 34 and 68 minutes?

First change 34 and 68 to a z scores using the formula:

Z = (x