With Casio (don't know the number, but the high end one) and Ti-36 you can do the z-distributions, but it'd be nice if there was t / chi square... Somewhere would be nice.
Yeah, when it comes to calculators, getting a better one isn't like the difference between an 83/84 and an 89 if you compare this to the benefits gained in a Calculus class. But if you do have what I used--a Ti-30, it can burn valuable time dealing with all the 1 var. and 2 var. statistics a slower way on the test, losing time to check over group work / get all of the missing points (that's what the competition seems like to me, as I found several missing parts / errors at the end but didn't get to fix them all)
A former Science Olympian that continues to work with his old team.