The conversion that can be used is 1 cm³ / mL
After multiplying by this conversion, we get:
1000 mL * (1 cm³ / mL) = 1000 cm³
Next, we may convert directly from cm³ to m³ by:
1 m = 100 cm
1 m³ = 100³ cm³
Using this conversion, we get the volume in m³ to be:
0.001 m³
The density of an object is mass / volume. These units are unusual but since you are reporting your answer in kg/L, the actual conversion is unnecessary
d = m/V
d = 7.2 kg / 9 L
d = 0.8 kg / L
