<p>I think the error in assuming that an applicant to Penn with SAT scores above the 75th percentile has a "better than even" chance of being admitted isn't in the correct calculation of the 75th percentile, but in failing to understand that even competitive applicants are never more than 50% assured of being admitted to any of the ultra-competitive schools. A person with a SAT-M score of 800 is certainly above the 75th percentile, but that fact alone does not mean that person has a "better than even" chance of admission based on that fact alone.</p>
<p>I think we all agree that understanding where an applicant falls in relation to benchmarks which are consistent from school to school is a valuable tool when used in conjunction with an understanding of other factors which bear on the issue: overall selectivity, weight of different factors such as GPA, EC's, etc. Outside of that framework it is of little help, however.</p>