Question

Stem-and-Leaf Plots

question: How many swimmers were younger then 30
Stem -- Leaf
0
1-- 1
2-- 3,9
3 --
4 -- 7
5-- 5,7,7,9
6-- 5,5,6,6,7,8,9
7-- 0,1
Key: 7-- 1 means 71

Answer 1

In total, there are 3 swimmers that are younger than 30.

Answer 2

We are looking for any swimmer's whose age begins with a 0, 1 or 2.

We look at the tree and count one swimmer (age 11) beginning with a 1 and two swimmers (age 23 and 29) beginning with a two.

In total, there are three swimmers younger than 30.