Data for Exercise 7.30

Statclas

Format

A data frame/tibble with 72 observations on two variables

class

class meeting time (9am or 2pm)

score

grade for an introductory statistics class

References

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

Examples


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 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 
#>