Inside a large tank at an oil refinery, three oils with different densities are blended together. There is no chemical reaction. The mixture contains $1200\,\text{kg}$ of oil with density $1100\,\text{kg m}^{-3}$, $1500\,\text{kg}$ of oil with density $860\,\text{kg m}^{-3}$, $4000\,\text{kg}$ of oil with density $910\,\text{kg m}^{-3}$. Determine the density of the mixture.
- A$927\,\text{kg m}^{-3}$
- B$957\,\text{kg m}^{-3}$
- C$1010\,\text{kg m}^{-3}$
- D$1080\,\text{kg m}^{-3}$