To get a flavor of what is to come this semester, we did a quick overview of bivariate relationships.
The covariance and correlation are fundamental measures of a bivariate relationship.
we took a look at how this works for a simple linear relation between two variables.
A couple of alternative representations of the same data:
We can also draw more general diagrams of correlations not equal in absolute value to one.
Finally, a little algebra shows how the covariance was invented: