Data for Exercise 7.42

`Wool`

A data frame/tibble with 20 observations on two variables

- type
type of wool (

`Type I`

,`Type 2`

)- strength
strength of wool

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

```
boxplot(strength ~ type, data = Wool, col = c("blue", "purple"))
t.test(strength ~ type, data = Wool, var.equal = TRUE)
#>
#> Two Sample t-test
#>
#> data: strength by type
#> t = 0.061752, df = 18, p-value = 0.9514
#> alternative hypothesis: true difference in means is not equal to 0
#> 95 percent confidence interval:
#> -13.20869 14.00869
#> sample estimates:
#> mean in group Type 1 mean in group Type 2
#> 136.7 136.3
#>
```