My hat's off to you, sir, for actually doing an experiment and measuring the result.
So Acetone is definitely far more volatile than gasoline (which is pretty volatile itself) at room temperature in a glass...and probably under all other conditions too.
I still don't see how acetone would magically produce more water. Whatever water is already in your tank (airborne or condensed) is already going to get sucked up by the ethanol and is going through your engine either way. Acetone isn't going to bring more water in. Acetone also isn't going to improve your fuel economy or power...