chickwts {datasets}R Documentation

Chicken Weights by Feed Type

Description

An experiment was conducted to measure and compare the effectiveness of various feed supplements on the growth rate of chickens.

Usage

chickwts

Format

A data frame with 71 observations on the following 2 variables.

weight

a numeric variable giving the chick weight.

feed

a factor giving the feed type.

Details

Newly hatched chicks were randomly allocated into six groups, and each group was given a different feed supplement. Their weights in grams after six weeks are given along with feed types.

Source

Snedecor (1948).

References

McNeil D (1977). Interactive Data Analysis: A Practical Primer. John Wiley & Sons. ISBN 978-0471026310.

Snedecor GW (1948). “60. Query.” Biometrics, 4(3), 213–215. doi:10.2307/3001566.

Examples

require(stats); require(graphics)
boxplot(weight ~ feed, data = chickwts, col = "lightgray",
    varwidth = TRUE, notch = TRUE, main = "chickwt data",
    ylab = "Weight at six weeks (gm)")
anova(fm1 <- lm(weight ~ feed, data = chickwts))
opar <- par(mfrow = c(2, 2), oma = c(0, 0, 1.1, 0),
            mar = c(4.1, 4.1, 2.1, 1.1))
plot(fm1)
par(opar)

[Package datasets version 4.6.0 Index]