# Calculator Question

1. Jan 29, 2008

### undrcvrbro

Cubic Regression

1. The problem statement, all variables and given/known data
(I was given a graph to enter into my calculator):

Let x represent time(in years) since 1980, and let y represent the corresponding U.S production of limousines. Enter the data in a graphing utility and find a cubic regression equation for the data.

2. Relevant equations
Calculator steps
Stat ---> Calc --->CubicReg... now what

3. The attempt at a solution
I have found the Cubic Regression equation but have forgotten how to make the equation itself appear in the y equals screen so that I can see the graph. I need that to answer the next part of the question.

I believe it should look something like this, but I'm not sure exactly how:

CubicReg L1,Y1,L2

Any help is greatly appreciated!

Last edited: Jan 29, 2008
2. Jan 29, 2008

### engineer23

What kind of calculator do you have?

3. Jan 29, 2008

### undrcvrbro

calculator

im using a TI-83 Plus

4. Jan 29, 2008

### engineer23

I have a TI-89, but this .pdf file may help you out.

Page 5 tells you how to enter data in list form. In your case, list 1 would be x = years since 1980 = 0, 1, 2, 3, .....
List 2 would be y variables and the entries would be the number of limousines that correspond to the year in the x column. Ex. In year 1980 (x=0), y = 100000 limousines
were produced.

Page 6-7 tell you how to select cubic regression from the STAT menu and enter the lists (L1, L2) that you want to analyze.

I wish I knew more about the TI-83, but hopefully you can find enough info in the pdf to do the problem.

5. Jan 29, 2008

### undrcvrbro

thank you

thank you very much, I'm sure that will help. I'll go go check it out right now.

6. Jan 29, 2008

### undrcvrbro

Thank You

THANK YOU! You area lifesaver, thank you for taking a little bit of time out of your day to save my whole night!