Need confirmation on this one.

I want to figure out the actual MPH based on engine RPM, gear selection, final Drive, and tire rotations per mile.

I need someone to verify my math on this one. I believe that the formula is something like this, but I don't know. I have the numbers

6000RPM / 1.56 / 3.73 / 757RPmi. x 60Minutes = 81.72MPH

It seems logical, but I just want to make sure I'm not missing any part of the equation. Thanks in advance.