I am trying to sync an .mp3 to an exercise, and can't seem to get the tempos to match up. Help?

Did you make a live recording or is this an mp3 from another source like a notation file or midi file? I'm not a Sibelius person, but is the problem importing the mp3 audio file or getting the tempos between a live recording and a notation file to sync up? Live audio will probably have a number of tempo fluxuations.

It is a song off of an album. Just an .mp3 from my itunes.