Data for Exercise 10.30 and 10.31

`Bookstor`

A data frame/tibble with 72 observations on two variables

- dollars
money obtained for selling textbooks

- store
a factor with levels

`A`

,`B`

, and`C`

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

```
boxplot(dollars ~ store, data = Bookstor,
col = c("purple", "lightblue", "cyan"))
kruskal.test(dollars ~ store, data = Bookstor)
#>
#> Kruskal-Wallis rank sum test
#>
#> data: dollars by store
#> Kruskal-Wallis chi-squared = 6.6476, df = 2, p-value = 0.03602
#>
```