field.concrete {SMPracticals}

Field Concrete Mixture Data

Description

Data from a 4x4 Latin square experiment on the efficiency of a field concrete mixer.

Usage

data(field.concrete)

Format

A data frame with 16 observations on the following 4 variables.

efficiency

a numeric vector

speed

a factor with levels 4, 8, 12, 16 mph.

run

order in which runs were performed each day

day

day on which runs were performed

Source

Unpublished lecture notes, Imperial College, London.

References

Davison, A. C. (2003) Statistical Models. Cambridge University Press. Page 435.

Examples

data(field.concrete)
fit <- lm(efficiency~run+day+speed,data=field.concrete)
anova(fit)
summary(fit)
fit <- lm(efficiency~run+day+poly(as.numeric(speed),3),data=field.concrete)
summary(fit)