A helium-filled balloon of the type used in long-distance flying contains (1.2 107 L) of helium. Let us say you fill the balloon with helium on the ground where the pressure is 793 mm Hg and the temperature is 14.5°C. When the balloon ascends to a height of 1 miles where the pressure is only 599. mm Hg and the temperature is -25°C, what volume is occupied by the helium gas? Assume the pressure inside the balloon matches the external pressure.