Linear Regression Activity

Answer the following questions on a separate piece of paper.

1. What was the equation for the line of best fit? Write your answer in the form y = ax + b.

2. What are the theoretical values of a and b? Explain your answer.

3. Measure the circumference and diameter of five additional lids, but use cm for units of length.

Create a table of values showing the diameter and circumference for each lid.

4. Add these values into the lists L1 and L2 in your calculator.

(To edit L1 and L2, press STAT, then ENTER. Use the arrow keys to move to the end of each list)

5. Graph the new data. Find an appropriate viewing window.

6. Find the line that best fits this updated set of values. Write your answer in the form y = ax + b.

7. Put the formula for the regression equation intoY1 in the Y= window. Then graph the equation.

8. How well does the line fit the data?

9. In measuring the lids, to what place value were you able to accurately measure the diameter and circumference?

10. In your answers to question 6, how many decimal place values would you use for expressing a and b?

Explain your reasoning.

11. Using values for a and b from question 10, enter the formula y = ax +b into Y2 in the Y= window,

12. Graph this new equation. How well does Y2 approximate the data?

After this lab you should be able to do the following:

1. Enter lists of data into your calculator.
2. Graph the data using an appropriate window.
3. Use your calculator to find the equation of the line of best fit.
4. Place the regression equation into the Y= window.
5. Plot the regression equation in the same window as the data.

You may need to review the presentation to practice these skills. They may be required for the next exam!!

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