Data for Example 7.11
Tensile
A data frame/tibble with 72 observations on two variables
plastic bag tensile strength (pounds per square inch)
factor with run number (1 or 2)
Kitchens, L. J. (2003) Basic Statistics and Data Analysis. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.
boxplot(tensile ~ run, data = Tensile,
col = c("purple", "cyan"))
t.test(tensile ~ run, data = Tensile)
#>
#> Welch Two Sample t-test
#>
#> data: tensile by run
#> t = -3.4505, df = 64.136, p-value = 0.0009946
#> alternative hypothesis: true difference in means between group 1 and group 2 is not equal to 0
#> 95 percent confidence interval:
#> -25.029593 -6.674665
#> sample estimates:
#> mean in group 1 mean in group 2
#> 102.3346 118.1868
#>