A scientist is interested in whether stretching before running 5 kilometers will improve a runner's time. The scientist decides that an experimental study is the best method to use to answer the question. One group of runners will run a 5-kilometer race without stretching, and a second group of runners will follow a specific stretching routine before running the race. The finishing times will be recorded, along with the group type for each runner.

mean = 23, standard deviation = 2

1. Assuming this group is representative of all adults who followed a specific stretching routine before running, use a normal distribution to estimate the probability that a randomly-selected adult could complete the race in fewer than 20 minutes after stretching. Round to 3 places.