`R/BSDA-package.R`

`Twin.Rd`

Data for Exercise 7.54

`Twin`

A data frame/tibble with nine observations on three variables

- twinA
score on intelligence test without drug

- twinB
score on intelligence test after taking drug

- differ
`twinA`

-`twinB`

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

```
qqnorm(Twin$differ)
qqline(Twin$differ)
shapiro.test(Twin$differ)
#>
#> Shapiro-Wilk normality test
#>
#> data: Twin$differ
#> W = 0.90449, p-value = 0.2792
#>
t.test(Twin$twinA, Twin$twinB, paired = TRUE)
#>
#> Paired t-test
#>
#> data: Twin$twinA and Twin$twinB
#> t = 2.4, df = 8, p-value = 0.04318
#> alternative hypothesis: true difference in means is not equal to 0
#> 95 percent confidence interval:
#> 0.07832989 3.92167011
#> sample estimates:
#> mean of the differences
#> 2
#>
```