I graduated early 80’s and my recollection was latin honors were based on percentage of class but I could be mistaken. Our suite had a summa, a magna and a cum laude – we were kind of the stealth nerds. I forget the exact GPA’s but the cum laude was around a 3.5, the magna a 3.7/3.8 and the summa around a 3.9. My S graduated a couple of years ago with a 3.75 in Econ and did not make latin honors. I was a bt shocked by the grade inflation at that time.