It also depends where you live. On most of the west coast you have to have a higher income than the average to live an average life. In the bay area you could consider people making 50-60k family income to be working class. Almost the same definition would apply to the LA area. Seattle is a bit cheaper but it is still more expensive than Lubbock,TX yadadamean. Also a lot of people in rich suburbia may have been living there for decades, back when it wasn't so rich and houses were dirt cheap.
Like my father's girlfriend's father, 91 years old this month and lived all his life in Bad Soden, now one of the richest towns in Germany...
Back on topic: What Al said and ...
1- I assume the median figure does not count retired households
2- I assume it does not count student households
3- I assume it does not count unemployed/underemployed
all of them wrong assumptions.
Well most neighborhoods don't have any, so in a sense yeah.
This. Exactly this.