Myers [1990] presents data on the number of fractures (y) that occur in the upper seams of
Question:
Myers [1990] presents data on the number of fractures (y) that occur in the upper seams of coal mines in the Appalachian region of western Virginia. Four regressors were reported: \(x_{1}=\) inner burden thickness (feet), the shortest distance between seam floor and the lower seam; \(x_{2}=\) percent extraction of the lower previously mined seam; \(x_{3}=\) lower seam height (feet); and \(x_{4}=\) time (years) that the mine has been in operation. The data are shown below.
a. Fit a Poisson regression model to these data using the log link.
b. Does the model deviance indicate that the model from part \(a\) is satisfactory?
c. Perform a type 3 partial deviance analysis of the model parameters. Does this indicate that any regressors could be removed from the model?
d. Compute Wald statistics for testing the contribution of each regressor to the model. Interpret the results of these test statistics.
e. Find approximate \(95 \%\) Wald confidence intervals on the model parameters.
Step by Step Answer:
Introduction To Linear Regression Analysis
ISBN: 9781119578727
6th Edition
Authors: Douglas C. Montgomery, Elizabeth A. Peck, G. Geoffrey Vining