Reputation: 1
My Problem:
I am using the Microsoft 365 Excel app for desktop.
My dataset comes from a programmed tool that collected raw data and automatically converted it to the final value using an equation I programmed into the tool.
I now realize that I want that raw data, "x", rather than the converted data, and I know that I will need to iteratively back calculate the equation for each converted value in the dataset to get that raw "x" value, but don't know how.
The equation is the following:
(4.824E-10)(x^3) - (2.278E-6)(x^2) + (3.898E-3)*(x) - 2.154
The converted values are each in their own cell in a single column in excel.
What I have tried:
I have tried solving the equation by hand and then plugging in the solved equation to excel, but my understanding is that I would have to do that individually for each data value in the data set.
I also tried the Solver Add-in, but as you can see in the images provided, I am getting an error saying that a formula needs to be provided in the "Set Objective" cell, even though I have provided that, so I am not sure if I am referencing the right sells to make Solver work correctly.
($F$5 contains the answer to the equation that I am trying to back step to find "x", which is cell $AE$5)
First image is a screenshot of how I filled in the Solver window.
Second image is the error I got when I hit "solve" in the Solver window.
I would like to make this an automated process for the entire dataset, if possible.
Thank you for any insight that you can provide.
Upvotes: 0
Views: 70
Reputation: 2027
A third-degree equation can be solved in several ways: with the help of the Solver
, with the help of the Goal Seek
, by the use of cyclic calculations, and finally there are analytical formulas that can be used and later the calculations can be performed using a Data Table
.
Here's an example in the screenshot.
Upvotes: 0