In the 2000 census, the so-called "long form" received by one of every six households contained 52 questions, ranging from your occupation and income all the way to whether you had a bathtub.
According to the U.S. Census Bureau, the mean completion time for the long form is 38 minutes. Assuming a standard deviation of 5 minutes and a simple random sample of 50 persons who filled out the long form, what is the probability that their average time for completion of the form was more than 45 minutes?