Question 3
Reilly's Law of Retail Gravitation is used by geographers to determine retail trade between two cities. The idea is
that with the formula, a researcher can draw a trade area boundary showing the area that a city will serve in terms
of retail sales. Please Reilly's Law of Retail Gravitation to answer the following question.
Please show your work and answer in a complete sentence.
Lawton (City A) is approximately 86.9 miles from Oklahoma City. The population of Lawton is 98,177 and the
population of Oklahoma City is 591,967 (City B). Using Reilly's Law of Retail Gravitation, the retail boundary from
between Lawton and Oklahoma City is shown on the map and is 25.12 miles from the center of Lawton. Calculate
a new boundary using the population of the entire Lawton (City A) metropolitan area (160,000)and state wether
the boundary would be north or south of the original boundary of 25.12 miles.
ANSWER:
Reilly's Law of Retail Gravitation
BP = distance between city a and b
$1 + \sqrt{\frac{population~b}{population~a}}$
For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac).
1+ square root of (population b/