Wow the advice on here.
Well if the third ranking student is much much lower than you on internal assessment, and that third ranked person does relaly well in HSC, then you might end up taking a few marks off them.
On the other hand, if they do quite terribly, you could lose a few marks.
Tbh, I came second, and a mate of mine came third in a subject where three people got a 91+ exam mark for this subject, then 4th ranked got 72.
In the end I only lost out 2 assessment marks to my exam mark (I got 92 exam, 90 assessment). My mate on third got 91 exam, 88 assessment.
In the end, because our teacher marked us really well for in class assessments, and fairly marked us, in the end we got assessment marks close enough to our exam marks.
Also, if you do terribly in your final HSC exam, and third who is a lot lower than you in school assessment does comparatively well compared to you in HSC, then you will actually gain a lot of marks off them.
The process is a lot fairer than people think. It will not have a major affect on your final result. The result you get will be the one you deserve rightfully for a whole year of assessment, not just a month of assessment.
Good Luck