Hello. I am trying to plug the following equations into Excel, but I am currently stuck:

Three Skinfold Sites (Chest, Abdominal, and Thigh sites from above, SUM3 is the sum of these sites in mm)

Bone Density =1.1093800 - (0.0008267 * SUM3) + (0.0000016 * SUM3²) - (0.0002574 * Age)

Body Fat Percentage =[(4.95/Bone Density) - 4.5] 100

I was able to calculate the Bone Density correctly with this:

=1.10938-(0.0008267*(B3+C3+D3))+((B3+C3+D3)*(B3+C3+D3)*0.0000016)-(0.0002574*23)

But now, I'm stuck. I need to plug the Bone Density solution into the Body Fat Percentage equation. I've tried breaking the equations up, but then I can't change the values in one cell without effecting the values in all the other cells.

What should I do next?

Thanks,
Gub