Problem: Grading on a Bell Curve
The mean and standard deviation of last semester's Exam 1 scores were 75.43 and 16.74 respectively. Imagine I wanted to define letter grades using a normal distribution (assuming this is appropriate). One possible grade distribution could be that the lowest 5% of students to earn Fs, the next 10% earn Ds, the next 35% earn Cs, the next 25% earn Bs, and the rest of the students earn As. Provide the Exam 1 scores that would separate these letter grades using the normal distribution. Your answer needs to be five normal graphs in StatCrunch where each shaded area on each graph shows the range of scores needed to earn the specific letter grade. Hint: the graphs for A and F will only have one value as a cutoff score whereas the graphs for a D, C, and B will have two cutoff scores (a low and a high score for that particular grade).