There are many people that are experts in that field. I am not, so I look to trust them.
The Health And Human Services department of the US Government puts the poverty line for a single person/ no children at $12,880/yr.
As these signs appear in Missouri, lets look at the cost of living in Greene County.
Let's start with the state's minimum wage: $9.45/hr. A lot higher than the federal wage. A person working 40 hours a week at minimum wage would make ~$19,800 a year. More likely, they're working 28 hours a week so their employer isn't required to provide benefits for them, meaning their annual ~$13,760 before taxes.
What is the cost of living* there? For a single person it would be:**
Food................$3,246
Daycare...........$0
Medical............$2,681
Housing...........$6,948
Transportation.$5,149
Civic................$1,956
Other...............$2,835
After taxes......$22,814
As FDR said back when the minimum wage was first established: "In my Inaugural I laid down the simple proposition that nobody is going to starve in this country. It seems to me to be equally plain that no business which depends for existence on paying less than living wages to its workers has any right to continue in this country." ***
*source: https://livingwage.mit.edu/counties/29077
**source: definitions of these terms can be found here - https://livingwage.mit.edu/resources/Living-Wage-Users-Guide-Technical-Documentation-2021-05-21.pdf
*** full speech can be read here: http://docs.fdrlibrary.marist.edu/odnirast.html