Back to back stem and leaf of age of students at "Barry's Ballroom Dancing Studio":
9...[1]...1, 2 , 3
7...[2]...0, 2, 2, 2, 4, 5
5...[3]...0, 0, 1, 7
5, 2...[4]...6, 7
3, 2, 0...[5]...2
4, 4, 2, 1...[6]...4, 4
the [1-6] is the centre column.
Liam decides to use a grouped frequency...