January temperature and latitude of US cities

Use this diagram to explain the dynamic linking of several scatterplots — selecting crosses in any scatterplot highlights these individuals in all of them. It can be done for any group of scatterplots or even dot plots of the same individuals.

The linked parts of this diagram are very specialised for the particular data set. Mention that the map is really a scatterplot of latitude against longitude.

Drag the red arrows on the residual plot to select the unusually hot and cold cities in January. Explain that these are unusually hot or cold in relation to their latitude, not necessarily absolutely. For example, Seattle is unusually warm for somewhere so far north, but it still much colder than places further south.

The data set contains the maximum January temperature (y, in degrees Fahrenheit) and latitude (x, in degrees) of various cities in the USA.

The typo in the original data set — the latitude for Jacksonville — has been corrected here.