Nickel concentrations (ppb) from four wells (five observations per year for each well). The Guidance Document has the label “Year” instead of “Well”; corrected in Errata.
EPA.09.Ex.10.1.nickel.df
A data frame with 20 observations on the following 3 variables.
Month
a numeric vector indicating the month the sample was taken
Well
a factor indicating the well number
Nickel.ppb
a numeric vector of nickel concentrations (ppb)