study score question?

[spm1]

so one of my friends last year got over 40 study scores for a number of subjects with grades like C, A+, A+??

how is this possible??? she went to a really academically strong school does that help at all ?

[Orb]

Your study score is calculated by adding three z scores together, that is effectively how many s.ds you were away from the mean for each component.

If you got a z score of -0.2 (which would be something like a C) for GA1 but z scores of 2 for GA2 and 2.5 for GA3 (which is almost near the max), once you add them together (after scaling for percentages) that's probably going to be still higher than the average 40 student who gets low A+s for all which is something like 1.5 + 1.5 + 1.5 (because GA3 is generally weighted more heavily).

A second option is that the C was just a grade from school, a strong cohort may scale that C up to a B+, A or even A+