Data used in Exercise 8.57

`Ability`

A data frame/tibble with 400 observations on two variables

- gender
a factor with levels

`girls`

and`boys`

- ability
a factor with levels

`hopeless`

,`belowavg`

,`average`

,`aboveavg`

, and`superior`

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

```
CT <- xtabs(~gender + ability, data = Ability)
CT
#> ability
#> gender hopeless belowavg average aboveavg superior
#> girls 56 61 54 21 8
#> boys 35 43 61 42 19
chisq.test(CT)
#>
#> Pearson's Chi-squared test
#>
#> data: CT
#> X-squared = 19.869, df = 4, p-value = 0.00053
#>
```