can you tell me how to do this chemistry problem (emperical)?

Question

A carbon compound has an empirical formula of CH2O and an approximate molecular weight of 117. What is its molecular formula?

Answer 1

To get the molecular formula you only need to divide the molecular weight by the weight of the emperical formula: It should come out to a whole number (or close to one).

117/(12 + 2 + 16) = 3.9

I'm presuming it should be 4, (they said the mw was approximate) Now, you multiply the empirical formula by 4 to get molecular formula.

CH2O >>> C4H8O4