Just how much does the magician damage formula

I understand that it is not linear anymore, so if I had base INT of about 938, how much at this point does one point in INT add to MA? Would someone be able to tell me how I can go about finding this out?

It was posted above that : Total Int / Total M.Att = Int:M.Att ratio.

so that means that if I take 938/my total MA (1200) = every point of INT adds 0.78 to MA???