A hot-air balloon is filled with air to a volume of 3.03x10^3 m^3 at 745 torr and 26 degree C. The air in the balloon is then heated to 54 degree C, causing the balloon to expand to a volume of 5.20x10^3 m^3. What is the ratio of the number of moles of air in the heated balloon to the original number of moles of air in the balloon?