The rotten smell of a decaying animal carcass is partially due to a nitrogen-containing compound called putrescine. Elemental analysis of putrescine indicates that it consists of 54.50% C, 13.73% H, and 31.77% N. Calculate the empirical formula of putrescine. (Hint: Begin by assuming a 100-g sample and determining the mass of each element in that 100-g sample.)