Let n be the number (in millions) of Americans impacted by bans or fees on single-use plastic bags, and let t be the number of years since 2010. In 2014, 18.3 million Americans were impacted by bans or fees on single-use plastic bags (Source: Earth Policy Institute).
Describe the situation with an ordered pair. Which variable should be described by the horizontal axis of a coordinate system? How about the vertical axis?