Start with Low and High number, then find equal percentage increase for 2 numbers in between

[Mathman]

A bit of a math and formula question.

Here is one example

I want to start with a low number and get to a predetermined high number and find the 2 numbers in the middle (2 and 3). The goal is to have the same percentage increase between each number.

Example

Start number is 10 (Fixed)
End number is 20 (Fixed)

I need

Start Number 10 (Fixed)
Second Number (Start Number X X%)
Third Number (Second Number X X%)
End Number (Third Number X X%) = End Number which is Fixed)

I can only do it threw goal seek which looks like this

The equal percentage for this example is 0.259920967880209

Start Number 10 (Fixed)
= Second Number (Start Number 10 X 0.259920967880209 = 12.5992096788021)
= Third Number (Second Number 12.5992096788021 X 0.259920967880209 =15.874008453042 )
End Number (Third Number 15.874008453042 X 0.259920967880209) = End Number which is Fixed 20)

I'm have multiple variations all different starting and end numbers but need a formula that could automatically fill in numbers 2 and 3 without using goal seek.

Please help!

MM

 

[Peter_SSs]

See if this does what you want.

Edit: BTW, I suggest that you update your Account details (click your user name at the top right of the forum) so helpers always know what Excel version(s) & platform(s) you are using as the best solution often varies by version. (Don’t forget to scroll down & ‘Save’)

20 04 19.xlsm
	A	B
1	Position	Number
2	1	10
3	2	12.5992105
4	3	15.87401052
5	4	20
Equal % Increase

Cell Formulas
Range	Formula
B3:B4	B3	=B2*(B$5/B$2)^(1/3)

 

[steve the fish]

If you want the percentage:

=(B1/A1)^(1/3)-1

 

[Mathman]

Come on Peter, that is awesome. You really helped me out.

Very greatful, Thank you!

MM

 

[Peter_SSs]

You're welcome. Thanks for the follow-up.

Did you catch the edit I made to my previous post?