Actually, I think Montague's theory is more accurately spoken.
Correct. Except that humid air is also less dense. Reading off of a psychrometric chart gives the density of 92 degrees at 80% RH of .06897 lbs per cubic foot. At 92 degrees and 14% RH it is at .07143 lbs per cubic foot. I do this kind of stuff for a living boys. If you take the FAA pilots test you would know this one.