Final answer:
Threshold population refers to the minimum number of people needed within a geographic area to sustain a business or service. A major league baseball team requires a large threshold, while establishments like Wal-Mart and Starbuck's Coffee shops require smaller populations to operate.
Step-by-step explanation:
A threshold population is the minimum number of people required within a certain geographic area to support a commercial establishment or service. This concept is crucial for businesses and service providers in determining the viability of a location. For example, a major league baseball team like the Milwaukee Brewers requires a threshold population of around two million people to sustain operations. A Wal-Mart store, which sells a wide range of products, has a threshold population of about 20,000, thus they can be found more abundantly. In contrast, a Starbuck's Coffee shop has a lower threshold of approximately 5,000 people, with a range of a few miles, making them even more numerous. Understanding threshold populations can help in planning and development within population ecology and urban geography.