Scores on a marketing exam are known to be normally distribu

Scores on a marketing exam are known to be normally distribute with mean and standard deviation of 60 and 20, respectively. The syllabus suggests that the top 15% of the students will get an A in the course. What is the minimum score required to get an A? Denote X to be the random variable \"score on the marketing exam\", and x to be the minimum score to get an A, choose from the followings the correct way to set up for solving x:

Solution

If you are on the top 15% of the class, the 85% of the class is lower than you. Thus,

OPTION D: P(X<=x) = 0.85 [ANSWER]