Zinc concentrations (ppb) at five background wells
(eight samples for each well). Nondetects reported as <7
.
EPA.92c.zinc.df
A data frame with 40 observations on the following 5 variables.
Zinc.orig
a character vector of original zinc concentrations (ppb)
Zinc
a numeric vector of zinc concentrations with <7
coded as 7
Censored
a logical vector indicating which observations are censored
Sample
a factor indicating the sample number
Well
a factor indicating the well number