Do you think I'll be able to get an ATAR of 78?

[random398]

Here are my marks:
english: B, A+ and the rest A's. For my practice exam I got an A (the only good mark, because I hardly studied mfor the practice exams) I feel confident about the exam and I feel like I have done quite a bit better than my practice exam, I think I may have gotten an A or A+
legal studies: got A average all year, except for my last SAC which I got a D in. Feel like I did OK in the exam, but could have done better. Maybe a B?
revolutions: B average, feel like my exam score will be a C pr something, maybe B if I'm lucky
Lit: A, B, C, C, A. Probably got C in exam
Psychology: One C, and the rest A's. Probably got around a B for the exam.

I'm really anxious at the moment, and I don't know what study scores I'm likely to get, I want to get at least a 78. Btw my cohort has done fairly well, and so have my classes. Thank you.