| alum {EngrExpt} | R Documentation |
As described in Nelson, Coffin and Copeland (2003), “ Over a 2-hour period, twenty-five 200 gm samples were drawn at random from a process that recycles plastic, and the amount of aluminum impurities in the sample in ppm was determined for each sample. ”
A data frame with 25 observations on the following variable.
ppmPeter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)
str(alum)
qqmath(~ ppm, alum, xlab = "Standard normal quantiles",
aspect = 1, ylab = "Amount of aluminum impurities (ppm)",
type = c("g","p"))
qqmath(~ log(ppm), alum, xlab = "Standard normal quantiles",
aspect = 1, type = c("g","p"),
ylab = "Natural log of amount of aluminum impurities (log(ppm))")