In a 1965 report, Lea discussed the relationship between mean annual temperature and the mortality rate for a type of breast cancer in women. The subjects were residents of certain regions of Great Britain, Norway, and Sweden. A simple regression of mortality index on temperature shows a strong positive relationship between the two variables.
The data set contains a single outlier. The scatterplot shows the regression line for the entire data set, and a separate regression line that excludes the outlier.