How old is that tree? One can determine how old a tree is by counting its rings, but that requires either cutting the tree down or extracting a sample from the tree’s core. Can we estimate the tree’s age simply from its diameter? A forester measured 27 trees of the same species that had been cut down, and counted the rings to determine the ages of the trees.

1. Find the correlation between Diameter and Age. Does this suggest that a linear model may be appropriate? Explain.

2. Create a scatterplot and describe the association.

3. Create the linear model.

4. Check the residuals. Explain why a linear model is probably not appropriate.

5. If you used this model, would it generally overestimate or underestimate the ages of very large trees? Explain.

Transcribed Image Text:

Diameter 1.8 1.8 2.2 4.4 6.6 4.4 7.7 10.8 7.7 5.5 9.9 10.1 12.1 12.8 10.3 14.3 13.2 9.9 13.2 15.4 17.6 14.3 15.4 11.0 15.4 16.5 16.5 (in.) Age (yr) 4 in 00 00 5 8 8 8 10 10 12 13 14 16 18 20 22 23 25 28 29 30 30 33 34 35 38 38 40 42