alum {EngrExpt}

Aluminum impurity amounts

Description

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. ”

Format

A data frame with 25 observations on the following variable.

ppm

amount of aluminum impurities (ppm)

References

Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)

Examples

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))")