I am using a map that shows population in square kilometers. Is there a way to convert that into population in square miles?
Not quite sure where the classification is coming from, but if it is coming from a field in the featureclass's table, why don't you just calculate a new field using the pop/km^2 field and the appropriate conversion factor to convert to pop/mi^2. Or is the map finished and you want to change the legend? Then you could convert the legend to graphics, explode the graphics and manually correct the label accordingly
If the population density pero km² is all you have, you could simply divide by 0.386102159 (or multiply by 2,589988110336) to get the population density in square miles.
or for conversions in general
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