A spherical balloon is made from a material whose mass is $2\mathrm{.}87$ kg$.$ The thickness of the material is negligible compared to the $1\mathrm{.}84-$m radius of the balloon. The balloon is filled with helium $($He$)$ at a temperature of $274$ K and just floats in air, neither rising nor falling. The density of the surrounding air is $1\mathrm{.}19$ kg$/$m$^3.$ Find the absolute pressure of the helium gas.