Data for Exercise 10.32

`Heating`

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

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

```
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
#>
```