I've been trying to do this problem but I would get confused and stuck..

Question

Consider a sample of a hydrocarbon at 0.959 atm and 298 K. Upon combustion the entire sample in oxygen, you collect a mixture of gaseous carbon dioxide and water vapor at 1.51 atm and 375 K. This mixture has a density of 1.391 g/L and occupies a volume four times as large as that of the pure hydrocarbone. Determine the molecular formula of the hydrocarbon.