Thank you for the reply.
So, I would need to get the weight of, let's say, 100 cc of the fluid and figure the density of the mixture?
PG's molar mass is 76.09 g mol−1, it's density is 1.036 g/cm³.
Water's molar mass is 18.01528(33) g/mol, it's density is 0.99820 g/cm3 at 20 °C (room temp).
What formula will I be using to determine % of each solution?
And should I be asking this be in a physics forum?