https://www.reddit.com/r/warcraftrumble/comments/1tyc4rx/beat_heroic_rag_with_243_average_maiev/
Heroic rag is level 29 and each level is 10% more health and damage multiplicatively so I was very underleveled. Raids are 2 player co-op so I played with a lot of random partners from the auto match maker. Most of them were mostly using level 30 and 31 stuff. To face heroic rag you have to beat the other 6 heroic bosses first, so I never saw anyone this low level who had passed the earlier bosses.