Also depending on how many unit 3&4 subjects you've taken the following contributes to atar:
If you've taken six subjects:
Your english/english language/eal/literature study score
Your three next best study scores
Only 10% of your two lowest study scores
So your two worst study scores don't really count for much, but that 10% can sometimes be just what you need for an atar score you need/want.
I'm unsure how this works for less than 6 year 12 subjects sorry, so hopefully someone else could explain this.
