How to make excel calculate the appropiate degression factor.

**kriobe** · 03-12-2011, 10:15 AM

Hi everyone, i'm new at the forum and also pretty beginner with excel, but i hope that some helpflul soul will help me with my problem!

It like this, I have given numbers in A1 (100) and A2 (200), the cells i want to create numbers in is A3,A4,A5.

A3 should be A1 * x, (100*x)
A4 = A3 * x, (100*x*x)
A5 = A4 * x, (100*x*x*x)

Also i want that the sum om A3-A5 should be equal to A2,
so what i really want is that Excel i setting x, which will be a number less than 1. How could i create this formula in the spreadsheet?

Would be greateful for some helpful answers!
/Kristian

**watersev** · 03-12-2011, 06:53 PM

hi, Kristian, this can be easily solved for example by solver add-in in Excel, see attachment and Excel help file for details.

As for the formula it is already existing: see Cardano method for solving cubic equation