This topics been discussed before,
http://bar-barians.forumotion.com/t1533-pull-up-muscle-upHowever to answer your question.
It doesn't quite work like that. If you can do X pull-ups and Y dips doesn't guaranty you will be able to do muscle-ups. Muscle-ups are a combination of raw power and technique. You need the strength to get above the bar and then the technique to switch your grip and push down to finish the move.
If you want some ideas, try focusing on doing weighted pull-ups (maybe +10% of you bodyweight) and straight bar dips. Once you've got 5-10 in a row have a go at doing the Muscle-up

Tim