A scatter plot is a convenient way to visually compare two numerical variables. For example, consider again the income per person variable (based on data from (Gapminder.org 2021)) and suppose this time, we are interested in visualising the relationship between this and the Happiness Index. Income per person can be represented along the horizontal \(x\) axis and happiness along the vertical \(y\) axis. Then, if we placed one point on the graph for each country located at the country's income per person on the \(x\) axis and happiness index on the \(y\) axis, this would be a scatter plot of the two variables:
Considering the above scatter plot, what observations can you make about the relationship between average income per person and average happiness score based on this data?
Scatter plots are also a helpful way for us to understand correlation. For example, consider the below scatterplots, and their associated correlations: