For a liquid, 0.500 cubic meters weighs 4590 N. What is the specific gravity of the liquid?
Divide the mass (Weight/g = 467.9 kg) by the volume (0.5 m^3). This will give you about 935 kg/m^3. The ratio of that to the density of liquid water (1000 kg/m^3) is the specific gravity.
The material is lighter than water.