I know a few ppl in the year above me who were quite good in maths, and I didn't see them getting an E4 in mx2.
One guy was a gun and always got 98-100 in all of his mx2 assessments and trials but in the end his HSC mark for mx2 is only 93
That goes to show that it's an individual's ability to do well, not the school he/she goes to. :D
That's great motivation for me to work hard since I go to a low ranked school as well.