India Four Two. I see what you're saying, but I disagree with JT.
After all, how's that possible with the empty weight? You can't know your moment. You can only know your weight and how far away from the CoG the weight is (i.e. the arm). From those you can derive the moment.
When you have worked out all the individual moments, you then have to work backwards (i.e. sum moments/sum weights) to derive the arm.