3. Plot a graph of quarterly data for real GDP and fullemployment GDP from 1970 to the present. (In the FRED database, full-employment GDP is called Real Potential GDP.) Which variable is “smoother”? Can you pick out the dates of recessions (1973–1975, 1980, 1981–1982, 1990–1991, 2001, and 2007–2009) on the graph?