The curve was for extra credit, the teachers give individual curves to each student depending on how much extra work they put in. Some kids got a 5 point curve, some kids got no curve, some even got a 50 point curve. It all depends on how well they did their project, not their intel or IQ rating.
On that note, I feel bad for this kid in my class. He got a 22%, no curve, and is required to do an alt. assignment to make the grade up.