Data for Exercise 7.58

`Speed`

A data frame/tibble with 15 observations on four variables

- before
reading comprehension score before taking a speed-reading course

- after
reading comprehension score after taking a speed-reading course

- differ
after - before (comprehension reading scores)

- signranks
signed ranked differences

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

```
t.test(Speed$differ, alternative = "greater")
#>
#> One Sample t-test
#>
#> data: Speed$differ
#> t = 0.99038, df = 14, p-value = 0.1694
#> alternative hypothesis: true mean is greater than 0
#> 95 percent confidence interval:
#> -2.490967 Inf
#> sample estimates:
#> mean of x
#> 3.2
#>
t.test(Speed$signranks, alternative = "greater")
#>
#> One Sample t-test
#>
#> data: Speed$signranks
#> t = 2.7691, df = 14, p-value = 0.007534
#> alternative hypothesis: true mean is greater than 0
#> 95 percent confidence interval:
#> 1.965284 Inf
#> sample estimates:
#> mean of x
#> 5.4
#>
wilcox.test(Speed$after, Speed$before, paired = TRUE, alternative = "greater")
#> Warning: cannot compute exact p-value with ties
#>
#> Wilcoxon signed rank test with continuity correction
#>
#> data: Speed$after and Speed$before
#> V = 100.5, p-value = 0.01144
#> alternative hypothesis: true location shift is greater than 0
#>
```