[slg]

That is a good point and the numbers aren't measuring the exact same thing (on the flip side of your example is the number of applicants to Harvard College who might not attend even if accepted). I didn't intend to reference them as some justification that the two schools are in any way equal. The only reason to really compare the two rates is because they have similar values and highlight the differences between the two schools. The toughest part of the College is getting in, the toughest part of the Extension School is getting out.