For starters, getting 75% for your school assessments is not called a 'Band 4'. Getting 95% in the exam is not called a 'Band 6'.
Don't take this badly, but you seem to have almost no understanding of the system, didn't a representative of BOS come to your school to at least attempt to explain the HSC system?
At school, you sit assessments and your trial. These all have different weightings and your final school 'raw' percentage is that total of marks. This percentage is the mark your school sends in to the Board of Studies, but it can be adjusted so long as it accurately represents your performance relative to your peers - for example, everyone gains 10% on their mark - the average is just raised by 10% as well, so no relative change.
Everyone gets a percentage, and you are ranked from 1st to last.
You then sit your HSC exams. These are marked, different option topics are scaled, and then a process called moderation occurs. Your school percentages are moderated/adjusted based on your cohort's HSC exam performance. For example, if all your HSC exam marks are within 70 and 80, then ALL your moderated assessment marks are adjusted to fit within 70 and 80. BOS will ensure the relative distances between you are your peers are accounted for. This means coming say 5th by 2% actually puts you in a better position than if you came 5th by 20%. But remember than all your marks are moderated to fit within that range of marks.
Your exam marks and your moderated assessment marks will now go through a process that will 'align' your marks according to standards set out by a BOS committee. That is to say, the mark/performance that they see is between a Band 5 and Band 6, is awarded a mark of 90. The mark/performance that is between the standards of a Band 4 and Band 5 is awarded an 80. So if your mark is halfway in the Band 5 region, it will be awarded 85.
This process is done to both your exam and school marks. Finally, your final mark is the average of your aligned HSC exam mark and your aligned moderated assessment mark, and it is this averaged mark that is awarded a Band. If your mark is 90 or above, it will be awarded a Band 6 etc.
You keep your own HSC exam mark, no one can 'take' that away. If you get 90 in the exam, you get 90 for your exam mark, regardless of rank. If you get 60 in your exam, you get 60 for your exam mark, and it doesn't matter if you are first or last or whichever rank.
Your school mark will be moderated so if you are significantly far from the top school assessment mark, then your moderated assessment mark will reflect that, but keeping in mind your cohort's exam performance. This is why doing well as a cohort is as important, if not more, than doing well individually.
A common misconception is that the (say) 5th highest exam mark is awarded to the 5th ranked student - this is absolutely wrong.
So given this 'renewed' understanding of the HSC system, do you still have any questions?
