Using drop down list value to change values in a formula based on what value is selected

Hi, in looking for help with a excel spread sheet I am currently trying to create, here is my problem.

I would like to use a drop down list value, to change 2 values in a formula for an equation. The drop down list ranges from 1 - 10, and depending on what number is selected I need to change 2 values in a formula to
Correct how the equasion work out its final value based on the selected drop down list number.

I have made the drop down list and placed it where I need it on the worksheet, I also has a list of the coefficient numbers I need to use, in the formula.

Here is why my formula looks like so far, =SUM(B11/'Coefficients '!C13*'Coefficients '!D13+B11)
I know this formula will not mean much based on my explanation, but the 2 coefficients (c13,d13) are the to values I need to change when I make a selection from my drop down list.

Here are some picture of what I am working on (hopefully) writing the from my tablet
image.jpg image.jpg

Hi,
In the place of coefficients!b13 and coefficients!c13, you can use vlookup formula.
Try this code " =SUM(B11/VLOOKUP(B12,coefficients!$B$4:$D$13,2,0)*VLOOKUP(B12,coefficients!$B$4:$D$13,3,0)+B11) "
Hope it will work
With regards
Nadarajan.

Thanks for your response, unfortunately when I applies the formula you suggested, has not worked, all it returned was #N/A

In the template sheet you should put your dropdown list value in b12. In template sheet ,in which cell you are using your
drop down list??Or upload your sample workbook and mention where you are putting your dropdown values! And mention
in which cell your result is needed ?