Fuel efficiency ratings for three types of oil heaters

Data for Exercise 10.32

Heating

Format

A data frame/tibble with 90 observations on the two variables

type

a factor with levels A, B, and C denoting the type of oil heater

efficiency

heater efficiency rating

References

Kitchens, L. J. (2003) Basic Statistics and Data Analysis. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.

Examples

boxplot(efficiency ~ type, data = Heating, 
        col = c("red", "blue", "green"))

kruskal.test(efficiency ~ type, data = Heating)
#> 
#> 	Kruskal-Wallis rank sum test
#> 
#> data:  efficiency by type
#> Kruskal-Wallis chi-squared = 6.264, df = 2, p-value = 0.04363
#>