A manufacturer of cheese supplies a major pizza chain from three different manufacturing locations. Samples from 6 different batches at each of three different plants were assayed for the percentage fat content.
A data frame with 90 observations on the following 3 variables.
the plant where the cheese was manufactured - a
factor with levels
the batch of cheese - a factor with levels
f. Note that batch
a from plant
A is not related to batch
a from plants
fat content of the cheese (%)
Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)
1 2 3 4 5 6 7 8 9 10
str(cheese) bwplot(batch ~ fat|plant, cheese, layout = c(1,3), strip = FALSE, strip.left = TRUE, xlab = "Percentage fat content of batches from three plants") dotplot(reorder(reorder(plant:batch, fat), as.numeric(plant)) ~ fat | reorder(plant, fat), cheese, strip = FALSE, strip.left = TRUE, layout = c(1, 3), scales = list(y = list(relation = "free")), aspect = 0.2, type = c("p", "a"), xlab = "Percentage fat content - lines join mean fat content per batch", ylab = "Batch within plant", jitter.y = TRUE)