The data set agsrs.dat also contains information on the number of farms in 1987 for the SRS of n = 300 counties from the population of the N = 3078 counties in the United States (see Example 2.5). In 1987, the United States had a total of 2,087,759 farms.
a Plot the data.
b Use ratio estimation to estimate the total number of acres devoted to farming in 1992, using the number of farms in 1987 as the auxiliary variable.
c Repeat (b), using regression estimation.
d Which method gives the most precision: ratio estimation with auxiliary variable acres87, ratio estimation with auxiliary variable farms87, or regression estimation with auxiliary variable farms87? Why?