So here is a little game for the comments section.

What do you think the median household income is in the US (as of 2003)?

What do you think the first, second, third, and fourth quintiles for household income is in the US (again, 2003)?

What is the lower limit for the top 5% of households?

Footnote: The quintiles cut all of the data in numerical order into five equal pieces. That is, the first quintile is the (least) income such that 20% of all households earn no more than that. The second quintile is at the level so that 40% of all households do not exceed that amount. The third quintile represents 60% of all households, and all but 20% are below the fourth quintile (representing the maximum of 80%).

No cheating! This survey is just informal to see what people think. I will post some student answers soon.