Dear Larry,
At the risk of appearing entirely anal, and reinforcing a probable reputation as being an entire CREEP on this thread, I'm really sorry, but I do not agree.
If you put a 10:1 granite/epoxy ( by weight) mix together, and the density of granite:epoxy is 2700 to 1300, you will end up with a total volume of epoxy (assuming no air voids) of about 17%.
Yes, if you put in a load of air, (probably not a good idea IMVVHO ), you can make the granite:epoxy:air ratio whatever you want as a percentage of the total volume of mix.
The volume ratio of the epoxy:granite within the mix will remain at 17% however.
My best suggestion would be to get rid of all the air you can. It really has little structural value.
There will be those who suggest that air is a further vital ingredient to damp down vibrations. Maybe, but I'm not going to venture into that discussion!
Best wishes,
Creepy Martin