Hello Guest,
(correction: Celia got 80% in her first three exams.)
Her reasoning is wrong because it would be right if she has written
one exam, this would be 80+942, which is 87%, but there are three
exams and not just one. So it equals: 80+80+80+944, which is 83.5%.
So her overall mark is no 87%, but it is 83.5%. It applies:
Sum of valuesNumber of values and that is the overall mark formula.
Straight