In ongoing economic analyses, the U.S. federal government compares per capita incomes not only among different states but also for the same state at different times. Typically, what the federal government finds is that "poor" states tend to stay poor and "wealthy" states tend to stay wealthy. Would we have been able to predict the 1999 per capita income for a state (denoted by y) from its 1980 per capita income (denoted by x)? The following bivariate data give the per capita income (in thousands of dollars) for a sample of sixteen states in the years 1980 and 1999 (source: U.S. Bureau of Economic Analysis, Survey of Current Business, May 2000). The data are plotted in the scatter plot in Figure 1, and the least-squares regression line is drawn. The equation for this line is y =6.99 +2.04x . 1980 per capita 1999 per capita income, x income, y (in $1000s) (in $1000s) Maryland 11.2 32.2 Iowa 9.7 25.7 38- Maine 8.4 25.0 36- South Dakota 8.1 25.1 34- Missouri 9.4 26.2 7.9 32- Alabama 22.9 California 12.0 29.8 30- Vermont 8.7 25.9 28- Utah 8.5 23.4 26 X x South Carolina 7.8 23.5 24 - Texas 10.0 26.5 22 - Oregon 10.2 27.1 20 Kentucky 8.2 23.2 8 10 11 12 13 Louisiana 8.8 22.8 Rhode Island 9.7 29.7 Figure 1 Mississippi 7.1 20.5