Data for Exercise 7.57

Habits

Format

A data frame/tibble with 11 observations on four variables

A

study habit score

B

study habit score

differ

B minus A

signrks

the signed-ranked-differences

References

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

Examples


shapiro.test(Habits$differ)
#> 
#> 	Shapiro-Wilk normality test
#> 
#> data:  Habits$differ
#> W = 0.89091, p-value = 0.1428
#> 
qqnorm(Habits$differ)
qqline(Habits$differ)

wilcox.test(Habits$B, Habits$A, paired = TRUE, alternative = "less")
#> Warning: cannot compute exact p-value with ties
#> 
#> 	Wilcoxon signed rank test with continuity correction
#> 
#> data:  Habits$B and Habits$A
#> V = 27, p-value = 0.3122
#> alternative hypothesis: true location shift is less than 0
#> 
t.test(Habits$signrks, alternative = "less")
#> 
#> 	One Sample t-test
#> 
#> data:  Habits$signrks
#> t = -0.51587, df = 10, p-value = 0.3086
#> alternative hypothesis: true mean is less than 0
#> 95 percent confidence interval:
#>      -Inf 2.741879
#> sample estimates:
#> mean of x 
#> -1.090909 
#> 

if (FALSE) {
library(ggplot2)
ggplot2::ggplot(data = Habits, aes(x = differ)) + 
           geom_dotplot(fill = "blue") + 
           theme_bw()
}