The composition of a certain MSW sample and specific weights

The composition of a certain MSW sample and specific weights of its various components are given below:

Specific weight (kg/m³) of the MSW sample is

Specific weight of MSW = % of component × specific weight
= .5 × 300 + .3 × 500 + .1 × 65 + 0.1 × 125 = 319 kg/m³.