Two Part Equations

[Gub]

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

[squiggler47]

=((4.95/(1.10938-0.0008267*(B3+C3+D3)+(B3+C3+D3)*(B3+C3+D3)*0.0000016-0.0002574*23))-4.5)*100

I am assuming that the 100 at the end means multiply!

or if you have your bone density formula already in A1 for example then

=(4.95/A1-4.5)*100

note that */ will always be calculated before +- so I removed the extra brackets for you!

[squiggler47]

=1.10938-0.0008267*(B3+C3+D3)+(B3+C3+D3)^2*0.0000016-0.0002574*23)

(B3+C3+D3)^2 is the same as squaring it

[Gub]

Ah, I do believe my middle school math teacher would be ashamed, but that's what happens when you crunch numbers in the early hours of the morning! Thank you very much squiggler47.

Now, how would I apply this equation to several different cells and make adjustments for rows without going back through and changing the row number manually?

Thanks again,
Gub

[squiggler47]

assuming that the formula is in row 3 (perhaps cell F3), all you need to do is copy and paste it into the next row(or rows) the row number will change automatically to refer to B4,C4,D4 etc