I have a problem on standard deviation, and I will need some help with it.

Problem:
Each professor in an English class give an A to students scoring above 90 and a F to those scoring below 60.

Professor 1 has a normal distribution with a mean of 74 and standard deviation 7

Professor 2 has a normal distribution with a mean of 78 and standard deviation 18.

Which professor gives the higher proportion of A's?

Thank you for your help!)

1 answer

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the two Z scores.