1. Pearson’s Correlation Coefficient
IB MATH SL CH 21B
Pearson’s Correlation Coefficient

2. Pearson’s product-moment correlation coefficient
Just observing points on a scatter plot to determine a linear relationship is inaccurate.
Pearson r is a more precise measure of strength of linear correlation between two variables.

3. Pearson R The values of r range from -1 to +1.
The sign of r indicates direction.
Positive Correlation - an increase in one of the variables will result in an increase in the other.
Negative Correlation – an increase in one of the variables will result in a decrease in the other.
The size of r indicates the strength of the correlation.
A value of r close to +1 or -1 indicates a strong correlation.
A value or r close to zero indicates a weak correlation.

4. Positive p NEGATIVE
Positive
Negative

5. Example with technology

6. TI-84+ Directions

7. Answer

8. IB MATH SL CH 21C
Line of Best Fit

9. Steps

10. Example

11. Answer

12. Kahoot.it