For a class of 43 students fora certain exam, the mean grade is 67 and the standard deviation is 7.

a) How many students should receive a C? (a c is between 74-79)
b) How many students should receive a B? (a B is between a 80-89)
c) what score is necessary to get an A?

1 answer

use this applet

http://davidmlane.com/hyperstat/z_table.html

enter your mean and SD
then click on the "between" and enter 74 and 79

multiply the probability factor by 43