Atmospheric pressure and boiling point

Mention that the data appear fairly linear in the scatterplot of the raw data on the left. The linked residual plot on the right reveals that all is not well. (Click on a cross on either plot to highlight the point on both plots.)

From the residual plot, there seems to be some curvature in the relationship with a single outlier. Click Delete outlier to remove this value from the data set.

A quadratic model will explain the curvature later.

In the mid 19th century, J. D. Forbes measured the boiling point of water (degrees Fahrenheit) and barometric pressure (inches of mercury) at 17 locations in the Alps and in Scotland.