Algebra 1 Common Core Student Edition, Grade 8-9

St e m - an d - Leaf Pl o t s

A stem -and-leaf plot is a display of data th at uses th e digits of th e d ata values. To

m ake a stem -and-leaf plot, separate each n u m b e r into a stem an d a leaf. A stem

an d leaf for the n u m b e r 2.39 is show n at th e right.

You can use a stem -an d -leaf plot to organize data. The data below describe the

price for the sam e n otebook at several stores.

N otebook Prices: $2.39 $2.47 $2.43 $2.21 $2.33 $2.28 $2.26

all digits

to the le ft of

last d ig it

last

'd ig it

— 2.3 | 9 '

I t

stem leaf

2.2 1 6 8

Use the firs t tw o 2.3^39

d ig its fo r the "s te m s ." 2.4 3 7

Use th e corresponding last

digits for the "leaves."

A rrange th e num bers in order.

Key: 2.4 | 3 means 2.43

You can use a back-to-back stem -an d -leaf plot to display two related d ata sets. The

stem s are b etw een two vertical bars, an d th e leaves are on each side. Leaves are

in increasing order from the stems. In th e back-to-back stem -an d -leaf p lot below,

3 14 11 represents a com m ute tim e of 43 m in in Town A a n d a co m m u te tim e of

41 m in in Town B.

r i

Daily Commute (min)

Town A Town B

6 6 4 3 4 1 1 4 5 7

9 8 6 4 4 4 5 0 2 2 2 4

5 2 1 0 6 4 5 8 9

8 7 6 6 4 2 7 3 6 7 9 9 9

Key: 7 3 means 73

2 7 | 3

2 7 means 72

,Y:;c

Ex e r c i se s

Make a stem -and-leaf plot for each set of data.

1. 18 35 28 15 36 10 25 22 15

3. 785 776 788 761 768 768 785

2. 18.6 18.4 17.6 15.7 15.3 17.5

4. 0.8 0.2 1.4 3.5 4.3 4.5 2.6 2.2

5. Make a back-to-back stem -an d -leaf plot of th e test scores

of the two classes below.

Class A: 98 78 85 72 94 81 68 83

Class B: 87 91 79 75 90 81 82 100

c

PowerAlgebra.com Skills H andbook 813