I agree with millie210 - spend some time showing your parents just how good CMU is. Find articles, ratings, big-name alums. Show them opportunities that will come from attending CMU (internships, potential employers) and the courses offered and the breadth of their highly-ranked programs. (For example, CMU has a very good writing program and drama, in addition to STEM subjects.) Show them how many students apply, and how few get in. They may start melting if they see how much research you’ve done on CMU, and what an accomplishment it is to have gotten in.