Posted by bikie on Tuesday, April 12, 2011 at 4:53pm.
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!)

Math  PsyDAG, Wednesday, April 13, 2011 at 12:03pm
Z = (scoremean)/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.