Hint: Latitude values for the northern hemisphere are positive. Longitude values for the western hemisphere are negative.
For example, the parameters of Williamstown, MA are 42.6848 and -73.2282.
(though interestingly, the sign doesn't affect the result, so long as you're consistent)
Note: To find the latitude and longitude of your location to six significant figures, visit a location-finder page such as this one (for US ZIP codes) or this one (for international cities) from your location.
Assumptions:
(a) The earth is a perfect spere with radius 3960 miles
(b) The two locations are at the centers of their respective towns
Hint: Latitude values for the northern hemisphere are positive. Longitude values for the western hemisphere are negative.