Once you have grouped your cities by state, you can create views on the set of states instead ot the set of cities: 2D graphs, parallel histograms, or even other maps can be used to find relationships on the states. The following view, for instance, displays the average latitude and longitude of each state. The shape of the United States is harder to recognize, but you can still get a sense of where each state lies on a map.

Alternatively, you can create subviews inside each state, letting you compare trends between states. Here, we have produced a 2D graph of housing cost vs. climate for each state in the data set:

Notice that in some states like California (CA) or Washington (WA), there is a correlation between both variables, whereas in other states like Colorado (CO) or Alabama (AL), there is no such correlation.