In: Statistics and Probability
Lumber Cutters – Lumber cutters wish to use readily available measurements to estimate the number of board feet of lumber in a tree. Assume they measure the diameter of the tree in inches at waist height. Develop a model that predicts board feet as a function of diameter in inches. Use the following data for your test:
x | 17 | 19 | 20 | 23 | 25 | 28 | 32 | 38 | 39 | 41 |
y | 19 | 25 | 32 | 57 | 71 | 113 | 123 | 252 | 259 | 294 |
The variable x is the diameter of a ponderosa pine in inches, and y is the number of board feet divided by 10.
a) Consider two separate assumptions, allowing each to lead to a model. Completely analyze each model.
i. Assume that all trees are right-circular cylinders and are approximately the same height
. ii. Assume that all trees are right-circular cylinders and that the height of the tree is proportional to the diameter.
b) For part a), use least squares to fit your proposed proportionality model. Compare your least-squares results with the model of the part a). Furthermore, find the bounds on the Chebyshev criterion and interpret the results.