A forester wishes to give an estimate of the total volume of trees in a sale of wood (N = 250). He takes a simple random sample (of size n = 12) from these trees and records the volume of each tree in the sample. He also measures the area of the base of each tree marked for sale. He then uses a ratio estimator for the total volume. Let X be the area of the base and Y the volume in cubic feet of a tree. The total area of the base of the 250 trees is ?X = 75 square feet. He collects the following data:

Tree Square-foot Tree Square-foot sampled basal area, x Volume, y sampled basal area, x Volume, y 0.3 0.6 0.5 0.5 0.4 0.8 DUAWN- 0.9 0.4 0.7 0.8 0.2 0.6