Do not compute average if student has string grade (INC or DRP) - will not compute average if string grade (INC, DRP) is found
Divide average by number of available grade - will get the average of available grades (average = sum of available grades / number of available grades)
Do not compute average if missing exam grade - will not automatically compute average if student is missing his/her exam grade
Custom Fixed average divisor - if checked, you can use a custom divisor in getting the grade average