Prep School for URM

Is going to a prep boarding school better for a minority when trying to get to an Ivy? It seems like that sometimes.

Closing thread. OP asked a very similar question earlier. Repetitive posts are not allowed per Terms of Service. Feel free to join the original discussion:
http://talk.qa.collegeconfidential.com/harvard-university/1960986-going-to-prep-boarding-school.html#latest