1. Objective: to draw and write trend lines; to use a graphing device to compute the line of best fit. Do-Now: Look at the 3 scatterplot below. Match the graph to the type of correlation. 1. Negative 2. Positive 3. No Correlation

2. Objective: to draw and write trend lines; to use a graphing device to compute the line of best fit. Warm-Up: **Pick up the new note guide, and a ruler from the front cart. Since it is a shortened period we are starting ASAP! Copy these two vocab words on your noteguide! Interpolation: finding values of data within your sample Extrapolation: finding values beyond your sample.

3. Guided notes!

4. Trend Line Shows the relationship between 2 sets of data Rough estimate; more than one possible correct answer; done by hand Line of Best Fit/Linear Regression Same idea as finding a trend line, but we use a calculator to do the dirty work for us More accurate; there will be one correct answer

5. Types of Correlation Positive when the values increase together Negative when one value decreases the other increases

6. Correlation Coefficient Be careful! The value of the correlation shows how well the line “fits” the data! Not how steep the line is! Values of r close to 0 imply that there is little to no linear relationship between the data. Values of r close to 1 imply that there is a positive linear relationship between the data. This means that as x increases that y also increases. Values of r close to -1 imply that there is a negative linear relationship between the data. This means that as x increases that y decreases.

7. Important Vocab Interpolation: finding values of data within your sample Extrapolation: finding values beyond your sample.

8. Example 1 : Kentucky State did a study to see if there was a correlation between test scores and the amount of watching TV. Here is the data that they found. Hours of TV Watched Test Scores 190 191 285 287 381 478 571 574 668 767 861 863

9. Steps: 1.Graph your data 2.Draw a trend line 3.Find the equation of your trend line 4.Use your graph to predict the scores at: 1.5 hours ______ and 12 hours _________ Tips to drawing a trend line: 1.Try to touch as many points as possible with being in the center of them 2.To find your slope, you can use points that it touched from your data, or perfect spots that it has touched.

10. Graphing Calculator Before we get started… Just a quick set-up! Go to catalog – Hit diagnostic on (This will allow you to calculate your correlation coefficient) If you didn’t do this, then your ‘r’ would be MIA

11. Let’s find the line of best fit and see how accurate our trend line! Go to Stat hit enter Go to Edit… hit enter Enter in the following data values into L1 and L2 Help your partner if you finish early Hours of TV Watched Test Scores 190 191 285 287 381 478 571 574 668 767 861 863

12. Computing the Line of Best Fit We need to calculate the linear regression model. Go to Stat hit enter Click the right arrow over to Calc Scroll down to 4:LinReg(ax+b) hit enter What information pops up? Hours of TV Watched Test Scores 190 191 285 287 381 478 571 574 668 767 861 863

13. Answer

14. Using a Graphing Calculator! We will work through one more example together Turn to page 321 #7 *Write down any notes or hints to help you find the Linear Regression using a calculator.

15. Classwork/Homework Practice 6.6 #s 1-3 *If you have a graphing calculator available at home, you can try #s 4-11 (this is not required) You will be assessed soon on how to find linear regression on a graphing calculator.