CMU has 7000 undergrads, of whom 600 are in the School of Computer Science. So, if you take a random CMU student who decided to start a company and looked for VC funding, you've got a <10% chance of an SCS alum and a 90% chance of a non-SCS student (assuming likelihood of starting companies is uniform, which who knows if it is but I have no reason to assume otherwise). Whereas at Stanford 100% of students had to get into Stanford.