First step in answering the question is to establish a balanced chemical reaction equation. More specifically, a combustion chemical equation.
CH4 + 2O2 ---> CO2 + 2H20
Then using dimension analysis:
[tex]4.60*10^{-3} g CH4 ( \frac{moleCH4}{16 g CH4}) * ( \frac{2mole O2}{mole CH4}) * ( \frac{32 g O2}{mole O2} ) = 0.0184 g O_{2} [/tex]