I had an 86% average in Gr 11, and am on track for a 93% average for Grade 12.
General EC’s
DECA School Chapter President
(Gr 11 DECA International Finalist)
Public Announcement Commitee President
Student Government Public Relations Officer
Started my own online business (5 clients, we have managed to brake even)
Developed and released 2 apps.
I can’t really “chance” you because there is no secret formula for admissions! I think your average may be slightly lower than what a lot of admitted waterloo cs students have, but write a solid AIF and you can get points added on to that. I think you have a fighting chance 
I’m an international student who was admitted early to UW’s Software Engineering this year, so I don’t really know my averages, but I can tell you that I developed and released 1 app in a team and did a bunch of music things (I know, completely unrelated haha) and I (somehow) was admitted! Emphasizing my prior point, writing a bomb AIF will bring you far (and also doing the Euclid competition!).