1. Correlation & Trend Lines
Unit 5
Correlation & Trend Lines

2. Correlation The relationship between two things (x, y)
x is the independent (explanatory) variable
y is the dependent (response) variable

3. Correlation Coefficient
Measure of the strength and the direction of a linear relationship.
-1 < r < 1

4. About r

5. Strong Positive
0.8 < r < 1

6. Moderate Positive
0.5 < r < 0.8

7. Weak Positive
0.2 < r < 0.5

8. Strong Negative
-1 < r < 0.8

9. Moderate Negative
-0.8 < r < -0.5

10. Weak Negative
-0.5 < r < -0.2

11. No Correlation
-0.2 < r < 0.2