Excuse me, I didn't look into your profile before.
badbackjim: I mean, I have a 74.96 average. Anybody have an idea why I got moved up?
Indeed, you were promoted without playing any ranked round recently. As a consequence, your average is unchanged.
I can only guess, but the only possible explanation that I see is that you might have played on mobile recently, and there, a tier promotion may be coupled with a level promotion because the games special to mobile play are considered practice rounds, not counting towards the average.