Chapter 2 An example via quantiles

We will now consider the concept of probability in the context of some of the concepts we discussed in previous topics, namely histograms and quantiles. Recall the Height variable from the survey data set which contains the responses of Statistics students to a set of questions (Venables and Ripley 1999):

Also recall that 160cm is the 0.1th quantile; that is, that students whose height is less than 160cm are among the shortest 10% of the sample:

We could think about this through the lens of probability as follows. Suppose a student from this sample of students were randomly selected. What is the probability their height would be less than 160cm? The answer is 0.1. This is because 160cm is the 0.1th quantile.


Venables, W. N., and B. D. Ripley. 1999. Modern Applied Statistics with s-Plus. 3rd ed. New York: Springer-Verlag.