Solve the following problem:
Q: It appears that over the past 45 years, the number of farms in the United States declined while the average size of farms increased. The following data provided by the U.S. Department of Agriculture show five-year interval data for U.S. farms. Use these data to develop the equation of a regression line to predict the average size of a farm by the number of farms. Discuss the slope and y-intercept of the model.
Year Number of Farms (millions) Average Size (acres)
1950 5.65 213
1955 4.65 258
1960 3.96 297
1965 3.36 340
1970 2.95 374
1975 2.52 420
1980 2.44 426
1985 2.29 441
1990 2.15 460
1995 2.07 469
2000 2.17 434
2005 2.10 444