Final answer:
The approximate volume of the iron bar is 100.5 cm³.
Step-by-step explanation:
To find the approximate volume of the iron bar, we can use the fact that the iron bar has the same mass as the aluminum bar. We know the mass of the aluminum bar is 813.6 g. The density of aluminum is 2.7 g/cm³, so we can calculate the volume of the aluminum bar by dividing its mass by its density: 813.6 g / 2.7 g/cm³ = 301.6 cm³.
Since iron is about three times the density of aluminum, the volume of the iron bar would be three times smaller than the volume of the aluminum bar. So, the approximate volume of the iron bar would be 301.6 cm³ / 3 = 100.5 cm³.