(Data file: landrent) These data were collected by Douglas Tiffany to study the variation in rent paid in 1977 for agricultural land planted to alfalfa. The variables are average rent per acre Y...

(Data file: landrent) These data were collected by Douglas Tiffany to study the variation in rent paid in 1977 for agricultural land planted to alfalfa. The variables are average rent per acre Y planted to alfalfa, average rent paid X₁
for all tillable land, density of dairy cows X₂
(number per square mile), proportion X₃
of farmland used as pasture, and X₄
= 1 if liming is required to grow alfalfa and 0 otherwise. The unit of analysis is a county in Minnesota; the 67 counties with appreciable rented farmland are included. Alfalfa is a high protein crop that is suitable feed for dairy cows. It is thought that rent for land planted to alfalfa relative to rent for other agricultural purposes would be higher in areas with a high density of dairy cows and rents would be lower in counties where liming is required, since that would mean additional expense. Use all the techniques learned so far to explore these data with regard to understanding rent structure. Summarize your results.