The Indiana State Department of Agriculture is concerned about the number of acres of farmland being withdrawn from farming. The department would like to propose new legislation to prevent this but would like to show the legislature what would happen if it does not act. Dewey Compost, the department’s statistician, regresses the number of acres used for farming in the state on time (1982 = year 1). Dewey finds the following:
= 2.743 - .027X
sb = .0007 Sy|x = .013 r2 = .89 sx = 16 = 29 n = 33
(a) How strong is the relationship?
(b) If Y is in millions of acres, how many acres of farmland will be lost in the next 10 years if the legislature does not act and if past practices continue?
(c) How many acres will be used for farming in 2015? Place a 90% confidence interval around this estimate.