Dataset:  shotgun_spread.dat

Source: W.F. Rowe and S.R. Hanson(1985). "Range-of-Fire Estimates from
Regression Analysis Applied to the Spreads of Shotgun Pellets Patterns: Results
of a Blind Study," Forensic Science International, Vol. 28, pp. 239-250

Description: Results of an experiment relating the square root of the area
spread of shotgun pellets to range of fire, for shotgun cartridge types.
Residuals show heterogeneity, and can be analyzed by weighted least squares.

Variables/Columns
Cartridge     8    /* 1=Winchester Western Super X 00, 2=Remington No. 4  */
Range (distance, in feet)   15-16
Square root of spread (inches)    20-24
Standard Deviation of sqrt(spread) for that range/cartridge type  26-32