Question: Foresters want to estimate the average age of trees in a stand. Determining age is cumbersome because one needs to count the tree rings on a core taken from the tree. In general, though, the older the tree, the larger the diameter, and diameter is easy to measure. The foresters measure the diameter of all 1132 trees and find that the population mean equals 10.3. They then randomly select 20 trees for age measurement.
a. Plot the data.
b. Estimate the population mean age of trees in the stand and give an approximate standard error for your estimate. Label your estimate on your graph. Why did you use the method of estimation that you chose?