Help getting an equation to excel

[BoycottValvoline]

Anyone know what function in Excel I have to use to write the equation, y*1.02^x=z? i have y and z already, so it would look like 2600*1.02^x=4200. Pretty sure I have to somehow get x alone on one side of the equal sign for it to be feasible, but remembering back to old math classes isn't suiting me terribly well this afternoon. I'm sure this isn't the typical Off-Topic post, but I figure you guys solve all my other problems I might as well ask you about this one.

 

[JS80]

Log or Ln will bring down an exponent.

 

[dullard]

Originally posted by: JS80
Log or Ln will bring down an exponent.

Yes, if you know algebra, you can solve this easilly by hand.

If you don't know algebra, you can solve this (or any other algebraic problem no matter how complex) in one easy step with Excel's Solver function. Note: Solver is by far the most useful and powerful Excel feature, but it is not installed by default. Go to the Tools menu, select Add-ins, and install the Solver feature. You'll need the CD.

 

[Connoisseur]

yup. x = (ln(z/y))/(ln(1.02))

 

[MrBond]

Wouldn't (z/y)^-1.2 = x also work?

Either way, pretty simple to put into Excel once you have it solved for X.

 

[dullard]

Originally posted by: MrBond
Wouldn't (z/y)^-1.2 = x also work?

No.