It's known that the commuting distance of U.S. workers averages 13 miles with a population standard deviation of 2 miles. An investigator wishes to determine if workers in her city commute more miles than the population average. She selects a random sample of 169 workers from her city, and finds the mean to be 15.5 miles. What will she conclude? For this 1-tail, directional test, use alpha = .05. What is step 1?