Computers purchased by university departments
13 17 13 8 7 10 10 21 18 17 |
19 15 15 23 12 12 15 27 19 23 |
6 2 9 11 5 18 20 24 15 14 |
11 2 4 4 13 10 13 19 25 14 |
11 4 14 12 23 19 17 16 17 13 |
7 9 12 11 30 19 4 11 18 18 |
24 15 13 12 6 17 27 3 10 7 |
1 14 22 16 10 2 7 9 5 21 |
18 17 18 12 15 13 13 15 6 25 |
13 15 5 28 20 19 14 11 14 4 |
8 10 7 23 18 24 |
There are multiple repeats of many values so an un-jittered dot plot superimposes many of its crosses and does not show the distribution of values.
A jittered dot plot separates out the crosses reasonably. However a stacked dot plot is best and, since there is a stack of crosses for each individual value, there is no information lost by 'grouping into classes'.
The data set is not real, but is supposed to be the number of recently purchased computers (under 2 years old) in each of the 106 departments of a large university.