Data for Example 7.18

Lowabil

Format

A data frame/tibble with 12 observations on three variables

pair

a numeric indicator of pair

experiment

score of the child with the experimental method

control

score of the child with the standard method

References

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

Examples


diff = Lowabil$experiment - Lowabil$control
qqnorm(diff)
qqline(diff)

shapiro.test(diff)
#> 
#> 	Shapiro-Wilk normality test
#> 
#> data:  diff
#> W = 0.95014, p-value = 0.6391
#> 
t.test(Lowabil$experiment, Lowabil$control, paired = TRUE)
#> 
#> 	Paired t-test
#> 
#> data:  Lowabil$experiment and Lowabil$control
#> t = 3.6035, df = 11, p-value = 0.004144
#> alternative hypothesis: true difference in means is not equal to 0
#> 95 percent confidence interval:
#>  1.427113 5.906220
#> sample estimates:
#> mean of the differences 
#>                3.666667 
#> 
# OR
t.test(diff)
#> 
#> 	One Sample t-test
#> 
#> data:  diff
#> t = 3.6035, df = 11, p-value = 0.004144
#> alternative hypothesis: true mean is not equal to 0
#> 95 percent confidence interval:
#>  1.427113 5.906220
#> sample estimates:
#> mean of x 
#>  3.666667 
#> 
rm(diff)