Professor Mann has determined that the final averages in his statistics course is normally distributed with a mean of 72 and a standard deviation of...

Professor Mann has determined that the final averages in his statistics course is normally distributed with a mean of 72 and a standard deviation of 5. He decides to assign his grades for his current course such that the top 15% of the students receive an A. What is the lowest average a student can receive to earn an A?