Never heard of that sort of system, and I'd never before heard of a valedictorian having a GPA too far north of the 4.6 region. Well...I suppose it's difficult

Never heard of that sort of system, and I'd never before heard of a valedictorian having a GPA too far north of the 4.6 region. Well...I suppose it's difficult to say if my experience applies generally (I'm sure it doesn't). However, at least in my high school, the absolute maximum possible was something like 4.6. You could, and we regularly did, calculate it based on your own classes. External classes would usually be counted either as honors or AP (unless it was a remedial course).