p13.7: Data Set for Problem 13-7
Description
The p13.7 data frame has 44 observations on the coal
mines of the Appalachian region of western Virginia.
Format
This data frame contains the following columns:
- y
- number of fractures in upper seams of coal mines
- x1
- inner burden thickness (in feet),
shortest distance between seam floor and the lower
seam
- x2
- percent extraction of the lower previously
mined seam
- x3
- lower seam height (in feet)
- x4
- time that the mine has been in operation (in years)
Source
Montgomery, D.C., Peck, E.A., and Vining, C.G. (2001)
Introduction to Linear Regression Analysis. 3rd Edition, John Wiley and Sons.