Calculate EXACT number to achieve an EXACT percentage

[glotgering]

I know the exact % I need to achieve. In this example column G2 is the target % of 67.201%.

G2 = 67.201% (This is the target %)
D4 = 4,250 (This is the number I need to increase to meet the percentage. The amount I need it to be is 4,681 for a difference of 431)

As the percentage of G2 Changes I need to calculate the EXACT number to increase D4 to meet the percentage. I have looked at several examples but all are more complicated than I need and I cannot figure it out.

Any help is greatly appreciated.

Thank you all very much.

 

[Eric W]

It's just basic algebra. You have this formula:

=(I2+I4)/(I4+O4)

that you want to set equal to G8 by changing the I2 value. This leads to this equation:

(X+I4)/(I4+O4)=G8

Now just solve for X.

(X+I4)=G8*(I4+O4)
X=G8*(I4+O4)-I4

Now take the X off and you have your formula.

=G8*(I4+O4)-I4

and since you want the difference between this value and the I2 value, just subtract that:

=G8*(I4+O4)-I4-I2

QED