Math Is Fun Forum

A professor at a local university noted that the grades of her students were normally distributed with a mean of 78 and a standard deviation of 15.

A. The professor has informed us that 16.6% of her students received grades of A. What is the minimum score needed to receive a grade of A? (Show the formulas, graph, and every step of the way in details).

B. If 12.1% of her students failed the course and received F's, what was the maximum score among those who received F? (Show the formulas, graph, and every step of the way in details).

C. Overall 5 students failed the test, how many students were enrolled in her course? (Show the formulas, graph, and every step of the way in details).

D. If 13% of the students received grades of B, what is the minimum score of those who received a B? (Show the formulas, graph, and every step of the way in details).

MIN:

E. If 50% of the students received grades of C, what is the minimum score of those who received a C? (Show the formulas, graph, and every step of the way in details).

MIN:

F. What is the minimum score of those who received a D? (Show the formulas, graph, and every step of the way in details).

MIN:

G. What percentage of students scored between 88 to 100 points?