Water Footprint A water footprint is a measure of the appropriation of fresh water. The per capita water footprint (in mega gallons) in the U.S. for a recent year can be approximated by a normal distribution, as shown in the figure.
(Source: Water Resources Research)

What water footprint represents the 80th percentile?
What water footprint represents the 29th percentile?
What water footprint represents the third quartile?