## References

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

## Examples

```
boxplot(mpg ~ truck, data = Trucks, horizontal = TRUE, las = 1)
summary(aov(mpg ~ truck, data = Trucks))
#> Df Sum Sq Mean Sq F value Pr(>F)
#> truck 2 0.70 0.35 2.5 0.124
#> Residuals 12 1.68 0.14
```