A spherical storage tank contains high pressure methane (molecular mass 16.04 g/mol). The tank is constructed out of a material with a design tensile strength of 109 MPa and a wall thickness of 3 cm, and has a diameter of 7 meters. The entire container is maintained at 4 degrees Celsius. How many metric tons of methane can be safely stored in this tank? (Recall that a metric ton is equal to 1000 kg or 1 Mg and assume ideal gas).