23. Movie lengths IT.' Exercise 21 looked at the running
times of movies released in 2005. The standard deviation
of these running times is 19.6 minutes, and the quartiles
are Qi 97 minutes and Q; = 119 minutes.
a) Write a sentence or two describing the spread in
running times based on
i) the quartiles.
ii) the standard deviation.
b) Do you have any concerns about using either of these
descriptions of spread? Explain.