200 km
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According to the scale of the map, 1 inch = 50 km. This signifies that for every 1 inch on the map, it represents an actual distance of 50 km.
The distance between the two cities on the map measures 4 inches. In order to find our answer, we need to multiply 4 inches by the scale conversion factor of 50 km per inch:
Hence, the actual distance between the two cities is 200 km.