Professor Elderman Has Given the Same Multiple Choice Final Exam

Multiple Choice

Professor Elderman has given the same multiple choice final exam in his Principles of Microeconomics class for many 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. Refer to Exhibit 7-4.What is the probability Professor Elderman's class of 36 has a class average below 78?

A) 0.1587
B) 0.5675
C) 0.8413
D) Cannot be determineD.