obviously sample sizes are small on any given day, but when I went there were 4 hopkins ugrads (myself included), 3 harvard, 2 stanford, 2 penn, 1 berkeley, and the other 3 or 4 were from smaller schools.
Stats are certainly only one thing, I've heard of people with 3.9, 43 who didn't get interviews, and those with 3.5, 30 who got in. In general, unless you've done something super extraordinary, anything below the 3.6, 31 range is probably unlikely.