stop stressing and just sit the rest of your exams. No point worrying about it now.
Your school is ranked 62 but I can't give you an estimate without knowing what your school is ranked for PDHPE.
For example, my school is ranked in the 20s, however our English would be ranked within the Top 5 whereas our Sciences (Phys, Bio, Chem etc) would be ranked well outside the Top 100. Our Humanities far surpasses our STEM subjects.
You will do well if you get above 85 raw, regardless of what you get put in from your school. If you're getting a 68 as a school mark, that gets moderated based off the rest of your cohort. There is really no way that anybody would be able to give you an estimate.
But here's a nice range - your mark will be between 80 and 100.
Doth welcome, best of luck with the rest of your exams.
