Solve the Problem $10 \%$ And Above the Bottom $60 \%$ C: Scores Below the Top 40\% and Above the Bottom

Multiple Choice

Solve the problem.
-A history teacher assigns letter grades on a test according to the following scheme:
A: Top 10\%
B: Scores below the top $10 \%$ and above the bottom $60 \%$
C: Scores below the top 40\% and above the bottom 20\%
D: Scores below the top $80 \%$ and above the bottom $10 \%$
F: Bottom $10 \%$ Scores on the test are normally distributed with a mean of 70 and a standard deviation of 12.9. Find the numerical limits for each letter grade.

A) A: Above 82
B: Between 73 and 82
C: Between 60 and 72
D: Between 53 and 59
F: Below 53

B) A: Above 82
B: Between 73 and 82
C: Between 60 and 72
D: Between 56 and 59
F: Below 56

C) A: Above 87
B: Between 77 and 87
C: Between 59 and 76
D: Between 53 and 58
F: Below 53

D) A: Above 87
B: Between 73 and 87
C: Between 59 and 72
D: Between 53 and 58
F: Below 53