2. Quantitative assessment of the strength of the relationship between x & y. It is the measure of the extent to which x & y are linearly related. *It is strong if the points lie close to a straight lint and is weak if they are widely scattered about a line.

3.  It’s a number between -1 and 1.  The closer it is to the ends, the stronger the positive or negative relationship.  It gives the strength and direction. 0 1 Strong Positive No Correlation Strong Negative

4.  www.whfreeman.com/tps4e www.whfreeman.com/tps4e

5. Think about z-scores of the x & y

9. xy 65 103 147 198 2112

10. xy 15219 27189 31195 42173 88121 92138 66152 51140

11. xy 2762 3887 4266 5849 1923 3151

12. If you are asked to interpret a correlation start by looking at a scatterplot of the data. Then be sure to address direction, form, strength, and outliers and put your answer in context.

13.  It does not depend on the unit of measurement.  It doesn’t depend upon which of the 2 variables is “x”  It’s between -1 and 1  It equals -1 or 1 if all points lie on a straight line  It is strongly affected by a few outliers

14. Scatterplots show relationships – not cause and effect.

15.  Apples: circumference, weight  College freshmen: shoe size, weight  People: age, grip strength  Drivers: blood alcohol, reaction time

16.  Create scatterplot  Find the correlation  Describe the association Fat (g)Sodium 19920 311500 341310 35860 391180 39940 431260

17.  There appears to be a (strong, weak, moderate) (positive/negative) (linear, nonlinear) relationship between _____ (give the x variable) and ______ (give the y variable)  Do not just say between x & y!

18. SAT-mathSAT-verbal 680780 450570 440550 610500 730720 530570 700600 640530 740800

19.  Page 160 (14-18, 21, 26)