Line of best fit.
Correlation coefficient r is how accurate the line of best fit is.
Perfect linear correlation
 If a straight line passes through every single point, then the variables are said to have perfect linear correlation
If a straight line passes through every single point, then the variables are said to have perfect linear correlation
Strong positive linear correlation

Moderate positive linear correlation

Weak positive linear correlation
 We dont know if its going up or down
We dont know if its going up or down