1. Unit 3 Sections 9.1

2. What we will be able to do throughout this chapter…  Determine relationships between two or more variables  Determine strengths of relationships  Determine what types of relationships exist  Determine what kind of predictions can be made from the relationship Section 9.1

3.  Correlation –a relationship between two variables.  Data is represented in ordered pairs (x, y)  x is the independent (or explanatory) variable.  y is the dependent (or response) variable. Section 9.1

4. Types of Correlation

5. Section 9.1 Types of Correlation

6. Constructing a Scatter Plot Section 9.1  Construct a scatter plot for the data obtained in a study of age and systolic blood pressure of six randomly selected subjects. SubjectAge (x)Pressure (y) A43128 B48120 C56135 D61143 E67141 F70152

7. Constructing a Scatter Plot Section 9.1  Construct a scatter plot for the data obtained in a study of the number of absences and the final grades of seven randomly selected students from a statistics class. Subject# of Absences (x)Final Grade (y) A682 B286 C1543 D974 E1258 F590 G878

8. Constructing a Scatter Plot Section 9.1  Construct a scatter plot for the data obtained in a study on the number of hours that nine people exercise each week and the amount of milk (in ounces) each person consumes per week. SubjectHours (x)Amount (y) A348 B08 C232 D564 E810 F532 G1056 H272 I148

9. Relationships  Example 1 – shows a positive relationship since as a person’s age increases their blood pressure tends to increase also.  Example 2 – shows a negative relationship since as the number of absences increases the final grade decreases.  Example 3 – shows no relationship since no pattern is discernable. Section 9.1

10.  Enter the data for your independent variable (x) into L1.  Enter the data for your dependent variable (y) into L2.  Press 2 nd then Y= to bring up your Stat Plot menu.  Hit Enter for Plot 1  Hit Enter to turn your Plot 1 on  Make sure the scatter plot is selected, Xlist is L1, and Ylist is L2.  Press ZOOM then 9 to bring up the Stat View  Your scatter plot should be in the window Section 9.1 Constructing a Scatter Plot Using a TI

11. Scatter Plot – Using the TI Section 9.1  A researcher conducts a study to determine whether there is a linear relationship between a person’s height (in inches) and pulse rate (in beats per minute). The data is shown in the table below. Display the data in a scatter plot and describe the correlation. Height (x)Pulse Rate (y) 6890 7265 88 70100 62105 7598 7870 6465 6872

12. Homework:  Pgs. 481-482 (1, 2, 9-18, 21a, 22a)  Read and take notes on Section 9.1 (pgs. 473-475)