To get the variables it needs we to look at our number keys from 1 to 6. If you look above them you will see that their second function is the L variablgget. We also need a comma to separate them. So press [2nd]->1 and then [,] and then [2nd]->2 to get the L1 and L2. Then, press [,] again and press [Vars], go to the

**Y-VARS** menu, selection

**Function** and select Y1. When you are done it should look like this

When you are done press [Enter] and it will find the linear regression. It will display for you the a and b coefficients for y=ax+b as well as store it in your Y1 position to graph.

If you go back to the [Y=] menu you will see how it is stored for you in equation form.

And if you hit the [Graph] button you will see how you line compares to the data.

We can see this is an OK fit but maybe we want to try a quadratic regression to try and get an even better fit.

**Quadratic Regression**

With the data stored we can easily now try a Quadratic Regression to see if it works any better. Once again hit the [Stat] button and go this time to choice #5 QuadReg.

We will give it the same variables again this time EXCEPT we want to put this equation in the Y2 position.

Once we press [Enter] we will see our coefficients again.

It will be stored in Y2.

And it will graph along with our data set and out linear regression line.