At what pressure will the balloon burst? (In atm)?

A particular balloon can be stretched to a maximum surface area of 1257 cm^2. The balloon is filled with 2.9 L of helium gas at a pressure of 748 torr and a temperature of 310 K. The balloon is then allowed to rise in the atmosphere. ume an atmospheric temperature of 273 K and determine at what pressure the balloon will burst. (ume the balloon to be in the shape of a sphere.)