Data for Example 7.17
A data frame/tibble with 20 observations on two variables
comprehensive strength (in pounds per square inch)
factor with levels
old indicating the
method used to construct a concrete block
Kitchens, L. J. (2003) Basic Statistics and Data Analysis. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.
wilcox.test(strength ~ method, data = Concrete, alternative = "greater") #> Warning: cannot compute exact p-value with ties #> #> Wilcoxon rank sum test with continuity correction #> #> data: strength by method #> W = 81, p-value = 0.0104 #> alternative hypothesis: true location shift is greater than 0 #>