Data for Example 7.19

Selfdefe

Format

A data frame/tibble with nine observations on three variables

woman

number identifying the woman

before

before the course self-confidence score

after

after the course self-confidence score

References

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

Examples


Selfdefe$differ <- Selfdefe$after - Selfdefe$before
Selfdefe
#> # A tibble: 9 × 4
#>   woman before after differ
#>   <int>  <int> <int>  <int>
#> 1     1      6     7      1
#> 2     2     10    12      2
#> 3     3      8     7     -1
#> 4     4      6     5     -1
#> 5     5      5     8      3
#> 6     6      4     6      2
#> 7     7      3     5      2
#> 8     8      8     8      0
#> 9     9      5     6      1
t.test(Selfdefe$differ, alternative = "greater")
#> 
#> 	One Sample t-test
#> 
#> data:  Selfdefe$differ
#> t = 2.1213, df = 8, p-value = 0.03334
#> alternative hypothesis: true mean is greater than 0
#> 95 percent confidence interval:
#>  0.1234006       Inf
#> sample estimates:
#> mean of x 
#>         1 
#> 
t.test(Selfdefe$after, Selfdefe$before, 
       paired = TRUE, alternative = "greater")
#> 
#> 	Paired t-test
#> 
#> data:  Selfdefe$after and Selfdefe$before
#> t = 2.1213, df = 8, p-value = 0.03334
#> alternative hypothesis: true difference in means is greater than 0
#> 95 percent confidence interval:
#>  0.1234006       Inf
#> sample estimates:
#> mean of the differences 
#>                       1 
#>