Invert Trendline Formula

I have a set of data that I graphed and put a trendline through

I’m looking to invert the formula so that instead of “y=…” I have “x…”

The reason for this is that I want to be able to input a Y value into a new formula and have it spit out and X value

y = 0.015148944696193x^6 - 0.247366569780115x^5 + 1.603305785101060x^4 - 5.692234929217150x^3 + 14.188270884610700x^2 - 30.860446329252900x + 51.534783142882400

Please see the screenshot below

2a.JPG

I think you've fallen into common trap when using trend line, looks like you are over-fitting the curve.

https://www.ma.utexas.edu/users/mks/...vefitting.html

The simplest way to "invert" the trendline is to switch the dependent and independent variables. In other words, create a series with X1:X100 for the y-axis and Y1:Y100 for the x-axis. Choose the simplest trendline that has a reasonably good RSQ, albeit maybe not the best RSQ. The trendline will always read y=...x... Just "translate" x to mean Y1:Y100 and y to mean X1:X100.

If you do choose a high-degree polynomial to fit your data, beware that it is probably only useful for interpolating data points. Such formulas tend to "blow up" when you try to extrapolate them.

Hey guys,

Thanks so much for all of your help. I looked at all of your options. For the time being I just switched my X and Y axis (how did I not think of that before lol)

I will, however, look at the article about over fitting the trendline.

Thanks so much again!