Data for Exercise 7.58

Speed

Format

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

References

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

Examples


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
#>