1. Investigating Scatter Plots Mr. J. D. Miles www.JovanMiles.com milesmath@gmail.com

2. Investigating Scatter Plots

3. Scatter plots are similar to line graphs in that each graph uses the horizontal ( x ) axis and vertical ( y ) axis to plot data points. Scatter plots are most often used to show correlations or relationships among data.

4. Investigating Scatter Plots Positive correlations occur when two variables or values move in the same direction.  As the number of hours that you study increases your overall class grade increases

5. Investigating Scatter Plots – Positive Correlation Study TimeClass Grade 055 0.561 167 1.573 281 2.589 391 3.593 495 4.597

6. Investigating Scatter Plots Negative Correlations occur when variables move in opposite directions  As the number of days per month that you exercise increases your actual weight decreases

7. Investigating Scatter Plots – Negative Correlation Work out timeWeight 0200 0.5205 1190 1.5195 2180 2.5190 3170 3.5177 4160 4.5170 5150 5.5168 6140 6.5150 7130 7.5170 8120 8.5130 9110 9.5115 10100 10.5120 1190 11.590 1280

8. Investigating Scatter Plots No correlation exists if there is no noticeable pattern in the data  There is no relationship between the number of shirts someone owns and their annual salary

9. Investigating Scatter Plots – No Correlation number of shirts ownedsalary 11 20 350 430 525 617 72 840 98 1025 1112 7 1319 1455 1571 169

10. Line of Best Fit A line of best fit is a line that best represents the data on a scatter plot. A line of best fit may also be called a trend line since it shows us the trend of the data  The line may pass through some of the points, none of the points, or all of the points.  The purpose of the line of best fit is to show the overall trend or pattern in the data and to allow the reader to make predictions about future trends in the data.

11. Use the data to create a scatter plot Sandwich Total Fat (g) (X) Total Calories (y) Hamburger9260 Cheeseburger13320 Quarter Pounder21420 Quarter Pounder with Cheese30530 Big Mac31560 Arch Sandwich Special31550 Arch Special with Bacon34590 Crispy Chicken25500 Fish Fillet28560 Grilled Chicken20440 Grilled Chicken Light5300

12. Scatter Plot of the Data

13. Things to remember A scatter plot with a positive correlation has X and Y values that rise together. A scatter plot with a negative correlation has X values that rise as Y values decrease A scatter plot with no correlation has no visible relationship The line of best fit is the line that best shows the trend of the data

14. Investigating Scatter Plots Mr. J. D. Miles www.JovanMiles.com milesmath@gmail.com