Data for Example 7.18
Lowabil
A data frame/tibble with 12 observations on three variables
a numeric indicator of pair
score of the child with the experimental method
score of the child with the standard method
Kitchens, L. J. (2003) Basic Statistics and Data Analysis. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.
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(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)