Question

how to put inequilities in class interval with these numbers
18.7
19.3
15.9
17.5
19.4
20.9
17.3
19.7
15.8
15
17.2
21.6
21.8
17.4
17
22
15.6
19.4
16.5
25.5
15.9
16.2
18.2
17.5