[IndispensableDestiny]

It looks like the commonly cited 80% Caltech four-year grad rate excludes incoming students who fail to complete required remedial courses, and it of course it excludes students that take longer than four years but still graduate. The remedial courses are not for college credits.

Cal Tech has an 8 percent admission rate. 99 percent of them graduated in the top 10 percent of their high school class. The middle 50 percent scored an 800 on their math SAT and 2240–2340 overall.

I don't think they do much remedial work.

[jjotto]

I believe IWB (and I) made a mistake identifying only the Caltech campuses

Thirty percent need remedial work, according to Cal State. Some campuses have very high rates of Pell Grant Affirmative Action enrollees.

https://www.nytimes.com/2017/08/04/us/california-today-cal-state-remedial-classes.html