Empirical Fomula

I was asked yesterday to remind how to do empirical formula questions. Here is an example and how to work it out.
Q.
Calculate the enpirical formula of a compound containing 38.70% Carbon, 9.67% Hydrogen and 51.60% oxygen.

A.
Step 1: Divide each percentage by the atomic mass (Mr) of each atom:
 
         C = 38.70/12 = 3.225          H= 9.67/1  = 9.67          O = 51.60/16 = 3.225

STEP 2: Divide by the lowest number (in this case 3.225):

                 
         C= 3.225/3.225  = 1             H= 9.67/3.225  = 3            O= 3.225/3.225 = 1

STEP 3: Write out empirical fomula - in this case CH3O