Two numerical variables

On watching this video, students should be able to:

1. Identify when and why a scatterplot is useful.
2. Interpret a scatter plot making note of the direction (positive or negative), form (linear or non-linear) and strength of the relationship, as well as any unusual observations that stand out.
3. Identify situations when the dimensionality of a scatter plot can be extended through use of colour and size of markers.
4. Explain what a correlation coefficient (r) measures, and it's appropriate to use.
5. Interpret a correlation coefficient and relate it to a scatter plot.