The density of block 25.7cm, width 25.5cm, the height of the block 23.3cm, volume 0.00152m^3, density 0.00295g/cm. Copper 8.94g/cm, brass 8.57g/cm,...

The density of block 25.7cm, width 25.5cm, the height of the block 23.3cm, volume 0.00152m^3, density 0.00295g/cm. Copper 8.94g/cm, brass 8.57g/cm, steel 7.75g/cm, aluminium 2.70cm.

What is the reference value for the density from the above?

What is %difference(%error) from reference value?