Data for Exercise 7.30
Statclas
A data frame/tibble with 72 observations on two variables
class meeting time (9am or 2pm)
grade for an introductory statistics class
Kitchens, L. J. (2003) Basic Statistics and Data Analysis. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.
str(Statclas)
#> tibble [72 × 2] (S3: tbl_df/tbl/data.frame)
#> $ class: chr [1:72] "9am" "9am" "9am" "9am" ...
#> $ score: int [1:72] 60 66 66 66 67 67 68 72 74 77 ...
boxplot(score ~ class, data = Statclas, col = "red")
t.test(score ~ class, data = Statclas)
#>
#> Welch Two Sample t-test
#>
#> data: score by class
#> t = 0.73184, df = 64.571, p-value = 0.4669
#> alternative hypothesis: true difference in means between group 2pm and group 9am is not equal to 0
#> 95 percent confidence interval:
#> -2.593904 5.593904
#> sample estimates:
#> mean in group 2pm mean in group 9am
#> 82.5 81.0
#>