The fact "a grocery store is for settlements of 300 or more people." is illustrated with the story:1. Stores cannot continue in business without sufficient sales2. A grocery store estimates how many customers it needs to generate sufficient sales.3. The grocery estimates that, if there were at least 300 people living nearby, they would shop in the grocery store.4. The money from the purchases made by the 300 people would be sufficient to pay bills and make an income.5. That's why in very small communities, you sometimes don't find stores.