>>13228990Assigning letter grades predates the GPA system. They actually predate numerical grades entirely. Passing was based on getting "satisfactory" or "good" marks. It wasn't until relatively recently that trying to standardize the concept of "passing" and "failing" pushed having numerical grades. So yes, it makes complete sense to operationalize letters as numerical variables for calculation.
>>13228988Depends on the school. 80-89 is usual, but some schools use a 7-point scale, so 85-92 is a B. More common in grade school than university. Some university courses are graded "on a curve" so scores are normalized and a B can be whatever the fuck the professor feels it should be. 1-2 standard deviations, maybe.
