Source: US Census. The median household income in the US is $50,502. This is some extremely useful data given that it is exploring over 114 million US households. If you want to know how most Americans are living this is a good figure to base your assumptions.
The myth that you have to wait 30 minutes or even an hour until you can swim after eating has been conventional wisdom for some time. The simple fact is, however, that swimming on a full stomach does not significantly impact your ability to swim.
This water movement and splashing around is called aeration and is used as one method of raising a pool's pH level. Some might say you can go swimming within 15 - 20 minutes after adding any chemicals, but it's better to stay safe. A 2 hour wait is fine after adding any pool chemicals.