Strength tests of two types of wool fabric

Data for Exercise 7.42

Wool

Format

A data frame/tibble with 20 observations on two variables

type

type of wool (Type I, Type 2)

strength

strength of wool

References

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

Examples

boxplot(strength ~ type, data = Wool, col = c("blue", "purple"))

t.test(strength ~ type, data = Wool, var.equal = TRUE)
#> 
#> 	Two Sample t-test
#> 
#> data:  strength by type
#> t = 0.061752, df = 18, p-value = 0.9514
#> alternative hypothesis: true difference in means between group Type 1 and group Type 2 is not equal to 0
#> 95 percent confidence interval:
#>  -13.20869  14.00869
#> sample estimates:
#> mean in group Type 1 mean in group Type 2 
#>                136.7                136.3 
#>