\Header{Formaldehyde}{Determination of Formaldehyde}
\keyword{datasets}{Formaldehyde}
\begin{Description}\relax
These data are from a chemical experiment to prepare a standard curve
for the determination of formaldehyde by the addition of chromatropic
acid and concentrated sulpuric acid and the reading of the resulting
purple color on a spectophotometer.
\end{Description}
\begin{Usage}
\begin{verbatim}data(Formaldehyde)\end{verbatim}
\end{Usage}
\begin{Format}\relax
A data frame with 6 observations on 2 variables.
\Tabular{rlll}{
[,1] & carb& numeric & Carbohydrate (ml) \\{}
[,2] & optden & numeric & Optical Density
}
\end{Format}
\begin{Source}\relax
Bennett, N. A. and N. L. Franklin (1954)
\emph{Statistical Analysis in Chemistry and the Chemical Industry}.
New York: Wiley.
\end{Source}
\begin{References}\relax
McNeil, D. R. (1977) \emph{Interactive Data Analysis.}
New York: Wiley.
\end{References}
\begin{Examples}
\begin{ExampleCode}
require(stats)
data(Formaldehyde)
plot(optden ~ carb, data = Formaldehyde,
     xlab = "Carbohydrate (ml)", ylab = "Optical Density",
     main = "Formaldehyde data", col = 4, las = 1)
abline(fm1 <- lm(optden ~ carb, data = Formaldehyde))
summary(fm1)
opar <- par(mfrow = c(2,2), oma = c(0, 0, 1.1, 0))
plot(fm1)
par(opar)
\end{ExampleCode}
\end{Examples}

