Usually they give the standard deviation. If you have that you can more precisely determine your grade. But to help you with this.... the mean is basically the average grade. I believe they set this to a low 2.8 or something like that, which is basically a C. So you can sort of determine your grade from there....
with those numbers, I'd say you would get a 3.0 (B) on the former and a 3.2 (B) on the later.