Transcript stem-and-leaf plot

6-9
6-9 Stem-and-Leaf
Stem-and-LeafPlots
Plots
Warm Up
Problem of the Day
Lesson Presentation
Course
Course
11
6-9 Stem-and-Leaf Plots
Warm Up
A set of data ranges from 12 to 86. What
intervals would you use to display this data
in a histogram with four intervals?
Possible answer: 10–29, 30–49, 50–69,
70–89
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6-9 Stem-and-Leaf Plots
Problem of the Day
What is the least number that can be
divided evenly by each of the numbers
1 through 12?
27,720
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6-9 Stem-and-Leaf Plots
Learn to make and analyze stem-and-leaf
plots.
Course 1
6-9 Stem-and-Leaf Plots
Vocabulary
stem-and-leaf plot
Course 1
6-9 Stem-and-Leaf Plots
A stem-and-leaf plot shows data
arranged by place value. You can use a
stem-and-leaf plot when you want to
display data in an organized way that
allows you to see each value.
Course 1
6-9 Stem-and-Leaf Plots
Additional Example 1: Creating Stem-and-Leaf
Plots
Use the data in the table to make a stem-andleaf plot.
Test Scores
75
86
83
91
94
88
84
99
79
86
Step 1: Group the data by tens
digits.
75 79
Step 2: Order the data from least
to greatest.
91 94 99
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83 84 86 86 88
6-9 Stem-and-Leaf Plots
Helpful Hint
To write 42 in a stem-and-leaf plot, write
each digit in a separate column.
4 2
Stem
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Leaf
6-9 Stem-and-Leaf Plots
Additional Example 1 Continued
Step 3: List the tens digits of the
data in order from least to
greatest. Write these in the
“stems” column.
Step 4: For each tens digit, record
the ones digits of each data
value in order from least to
greatest. Write these in the
“leaves” column.
Step 5: Title the graph and add a key.
Key: 7 5 means 75
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75 79
83 84 86 86 88
91 94 99
Test Scores
Stems
Leaves
7
8
9
5 9
3 4 6 6 8
1 4 9
6-9 Stem-and-Leaf Plots
Check It Out: Example 1
Use the data in the table to make a stem-andleaf plot.
72
84
Test Scores
88
64
79
83
76
74
61
67
Step 1: Group the data by tens
digits.
61 64 67
Step 2: Order the data from least to
greatest.
83 84 88
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72 74 76 79
6-9 Stem-and-Leaf Plots
Check It Out: Example 1 Continued
Step 3: List the tens digits of the data
in order from least to greatest.
Write these in the “stems”
column.
61 64 67
72 74 76 79
83 84 88
Step 4: For each tens digit, record the
ones digits of each data value
in order from least to
greatest. Write these in the
“leaves” column.
Test Scores
Stems
Leaves
Step 5: Title the graph and
add a key.
Key: 6 1 means 61
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6
7
8
1 4 7
2 4 6 9
3 4 8
6-9 Stem-and-Leaf Plots
Additional Example 2: Reading Stem-and-Leaf
Plots
Find the least value, greatest value, mean,
median, mode, and range of the data.
The least stem and least leaf
Stems
give the least value, 40.
4
The greatest stem and
5
greatest leaf give the
6
greatest value, 94.
7
8
Use the data values to find the
mean (40 + … + 94) ÷ 23 = 64. 9
Leaves
00157
1124
333599
044
367
14
Key: 4 0 means 40
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6-9 Stem-and-Leaf Plots
Additional Example 2 Continued
The median is the middle
value in the table, 63.
To find the mode, look for
the number that occurs
most often in a row of
leaves. Then identify its
stem. The mode is 63.
The range is the difference
between the greatest and
the least value. 94 – 40 =
54.
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Stems
4
5
6
7
8
9
Leaves
00157
1124
333599
044
367
14
Key: 4 0 means 40
6-9 Stem-and-Leaf Plots
Check It Out: Example 2
Find the least value, greatest value, mean,
median, mode, and range of the data.
The least stem and least leaf
Stems
give the least value, 30.
3
The greatest stem and
4
greatest leaf give the
5
greatest value, 85.
6
Use the data values to find the
7
mean (30 + … + 85) ÷ 23 = 55.
8
Leaves
02568
1134
456999
124
569
15
Key: 3 0 means 30
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6-9 Stem-and-Leaf Plots
Check It Out: Example 2 Continued
The median is the middle value in the table, 56.
To find the mode, look for
the number that occurs
most often in a row of
leaves. Then identify its
stem. The mode is 59.
The range is the difference
between the greatest and the
least value. 85 – 30 = 55.
Stems
3
4
Leaves
02568
1134
5
6
456999
124
7
8
569
15
Key: 3 0 means 30
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6-9 Stem-and-Leaf Plots
Lesson Quiz: Part I
1. Make a stem-and-leaf plot of the data.
42 36 40 31 29 49 21 28 52 27 22
35 30 46 34 34
Stems
Leaves
2
1 2 7 8 9
3
0 1 4 4 5 6
4
0 2 6 9
5
2
Key: 3 | 0 means 30
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6-9 Stem-and-Leaf Plots
Lesson Quiz: Part II
Find each value using the stem-and-leaf plot.
2. What is the least value? 21
3. What is the mean?
34.75
4. What is the median?
34
5. What is the mode?
34
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