Notice that the density is given in terms of g/mL, while the volume is in gallons and the mass to be determined is in pounds. We cannot solve the problem without being consistent with the units. So, convert the density to lb/gal knowing that: 1,000 g = 2.2 lb and 1 gal = 3785.41 mL.
Density = 0.749 g/ml * 2.2 lb/1,000 g * 3785.41 mL/1 gal
Density = 6.2376 lb/gal
Mass = 6.2376 lb/gal*19.2 gal
Mass = 119.76 lbs
