A 576 kg weather balloon is designed to lift a 3670 kg package. What volume should the balloon have after being inflated with helium at standard temperature and pressure in order that the total load can be lifted? Am i missing something or is there more to this question there , there seems. The ballon with a certain mass wants to lift an iditional mass therefore the combinded mass of the baloon is 4246 Kg The dnesity of Helium at STP is 0.18 kg/m^3 and the relationship describing density is : D=M/V rearrange for volume and and get Volume= mass/ density V=4246 kg/ 0.18kg/m^3 V=23588.89 m^3 which is wrong...what am i missing here??