This all is highly technical, but without getting into all the technical details of the calculations:
graduates/ # starts = completion rate
placed/ # graduates = placement rate
placed/ # starts = percentage starts who are eventually placed.
= Completion rate * placement rate
In the case of Everest, that's about
0.6 * 0.6 = 0.36, or about 35 to 40% of the students who start are placed.