The density of water is $1000 \mathrm{~kg} / \mathrm{m}^{3}$ and the density of copper is 8900 $\mathrm{kg} / \mathrm{m}^{3}$. Which of the following statements is incorrect?
(a)
$\frac{\text { The density of a certain volume of copper }}{\text { The density of the same volume of water }}=8.9$
(b) $\frac{\text { The volume of a certain mass of copper }}{\text { The volume of the same mass of water }}=8.9$
(c) $\frac{\text { The weight of a certain volume of copper }}{\text { The weight of the same volume of water }}=8.9$
(d) $\frac{\text { The mass of a certain volume of copper }}{\text { The mass of the same volume of water }}=8.9$