## Essential University Physics: Volume 1 (3rd Edition)

We know that the buoyant force is given as $B=\rho_{air}Vg$ The weight of the Styrofoam is given as $W=mg=\rho_{S}Vg$ Now we can find the percent error as $\frac{B}{W}\times 100=\frac{\rho_{air}Vg}{\rho_SVg}\times 100=\frac{\rho_{air}}{\rho_S}\times 100=\frac{1.2}{160}\times 100=0.75\%$