<p>BTW I never described the right table to use (if the model was valid). The right table would be the SAT scores of Northwestern applicants by percentile. The wrong table, which the OP used, is the table of SAT scores all all HS students by percentile. But the saying GIGO still applies.</p>
<p>jdelavelle, I understand what you're trying to say, but you way over-estimate chances. A lot of people just don't realize how intense the competition is for the small number of spaces at the elite schools. You depict a valedictoria, SAT 1550, whom you describe as "This kid has a good chance of making it. I would say there is an 60% chance of admission". And from the limited view of HS this person does sound like a god; you may see someone this strong only every few years (if that). Yet in a country with about 3 million HS graduates each year, such numbers are not as rare as you might think.</p>
<p>Brown does not give the figures for the exact person you describe. However they do say that only 35% of valedictorians who applied were accepted, and for those with Verbal or Math SAT scores of 750-800 only 26% were accepted! The competition is much harder than you predicted.</p>
<p>The Brown website is at <a href="http://www.brown.edu/Administration/Admission/gettoknowus/factsandfigures.html%5B/url%5D">http://www.brown.edu/Administration/Admission/gettoknowus/factsandfigures.html</a></p>