Professor Ted Woodruff has given the same multiple choice final exam in his Principles
Professor Ted Woodruff has given the same multiple choice final exam in his Principles of Microeconomics class for last 10 years. After examining his records from the past 10 years, he finds that the scores have a mean of 76 and a standard deviation of 12. What is the probability Professor Woodruff’s current class with 36 sample students has a class average below 78?