Injury level versus seatbelt usage

Data for Exercise 8.24

Seatbelt

Format

A data frame/tibble with 86,759 observations on two variables

seatbelt

a factor with levels No and Yes

injuries

a factor with levels None, Minimal, Minor, or Major indicating the extent of the drivers injuries

Source

Jobson, J. (1982), Applied Multivariate Data Analysis, Springer-Verlag, New York, p. 18.

References

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

Examples

T1 <- xtabs(~seatbelt + injuries, data = Seatbelt)
T1
#>         injuries
#> seatbelt  None Minimal Minor Major
#>      Yes 12813     647   359    42
#>      No  65963    4000  2642   303
chisq.test(T1)
#> 
#> 	Pearson's Chi-squared test
#> 
#> data:  T1
#> X-squared = 59.224, df = 3, p-value = 8.61e-13
#> 
rm(T1)