“Weil (1970) in Table 1 gives the results from an experiment comprising two treatments. One group of 16 pregnant female rats was fed a control diet during pregnancy and lactation, the diet of a second group of 16 pregnant females was treated with a chemical. For each litter the number \(n\) of pups alive at 4 days and the number \(x\) of pups that survived the 21 day lactation period were recorded.” (Williams, 1975, p. 951).
data(rats)A data frame with 32 observations on the following 3 variables.
A factor with levels CTRL and TREAT
A numeric vector: the number of pups alive at 4 days.
A numeric vector: the number of pups that survived the 21 day lactation.
Weil, C.S., 1970. Selection of the valid number of sampling units and a consideration of their combination in toxicological studies involving reproduction, teratogenesis or carcinogenesis. Fd. Cosmet. Toxicol. 8, 177-182.