How do curves ususally work? How many Standard Deviations above the mean usually puts you in the A- range?

Question

Basically, in my biochemistry course, I've gotten the following grades:

Quiz1: 40.0 / 50; mean= 35, s.d.=9, I got abtout 0.5 sd above avg

Quiz 2: 42.5/ 50; mean= 30, s.d.=7, I got abtout 1.5 sd above avg

Quiz 3: 41.0 / 50; mean= 31, s.d.=7, I got abtout 1.5 sd above avg

How many staandard deviations above average usually qualifies for an A, or an A-, or even a B+?

Thanks a bunch!

Answer 1

er..wow...I've never seen grades calculated by standard deviations before...sorry i wish i could help