How to calculate a multi-variable formula from a table of data

Question

I have a table of several independent variables that I need to calculate a formula from to generate the dependent variable. Though trial I have come up with a value for the dependent variable. For example, I have a table like this:

x1 | x2 | x3 || z(value found by experiment)
-------------------
1  | 2  | 3  || 10
3  | 4  | 5  || 14
2  | 3  | 3  || 15
1  | 2  | 7  || 9

now I want a formula such that:

f(x1,x2,x3) = z

Now how do I go through and get the value? Can you point me to some resources?

I feel like I should remember this from my school days, but I dont.

Also: Do you know any tools that will do this for me? I have excel, but I cannot figure out how to do regression with more than one variable.

Answer 1

You are talking about regression analysis. If the relationship is linear, then it is multiple linear regression (more than one independent variables, one dependent variable, linearrelationship) See the links for further info

Edits: To do this analysis with Excel 2007: You must first enable the Analysis ToolPak in Office logo (top left) > Excel Options > Add-Ins > Manage (dropdown menu: Excel Add-Ins) > Go > Check Analysis ToolPak > Ok

Then you can choose Analysis > Regression in the Data ribbon where you can specify multiple columns as your input range. You can find a guide here about more details to use the regression tools, it's for an older version of excel but the regression tool is the same.