<p>
No need to explain–I’ve been following Penn’s admission stats for probably longer than you’ve been alive. 
My point was merely that the vast majority of those who apply to and are accepted by Penn come from high schools that don’t even provide class rank. Plus, as legendofmax pointed out, the admissions process at Penn (and other top schools) is holistic, so that one parameter alone (e.g., class rank) is not determinative. </p>
<p>Furthermore, there’s a new sheriff in town (Furda), and Penn has suddenly dropped the detailed admissions stats for various class ranks and SAT levels from its web site, after having included those stats for at least the past several years. To me, that signals a change in emphasis, although I’m not sure exactly how it will play out in the admissions process. But at the very least, Penn is indicating that it doesn’t want applicants to focus on specific class ranks and SAT ranges in evaluating their chances of admission.</p>
<p>Finally, just skim a few of the recent ED and RD decision threads in the Penn forum, and you’ll quickly see that admissions decisions often do not correlate with class rank and/or SATs.</p>