A spherical balloon is made from a material whose mass is 3.00-kg. The thickness of the material is negligible compared to the 1.5-m radius of the balloon. The balloon is filled with helium (He) at a temperature of 305-degrees K and just floats in the air, neither rising nor falling. The density of the surrounding air is 1.19-kg/m^3. Find the absolute pressure of the helium gas.