The time required to make 900 gallons of synthetic rubber at a plant in South America in a recent year was normally distributed with a mean of 15 hours and a standard deviation of 2.5 hours. What is the probability that it will take more than 17 hours to make 900 gallons of synthetic rubber?
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.