The students in my class have Exam 1 scores which are normally distributed with a mean of 75 and a standard deviation of 9. If a student is selected at random,
a. What is the probability the student will have a score of more than 90 (an A)?
b. What is the probability the student will have a score of less than 60 (an F)?
c. What is the probability a student will have a score between 80 and 89 (the B range)?
d. What is the range of scores for the middle 50% of the student scores?
e. What is the range for the central 99.7% of the scores?
f. What is the lower cut-off for the top 3/4 of the students?