Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Warm Up
Jason deposits $200 in an account that earns
3.6% simple interest. How long until the total
amount is $300?
Almost 14 years
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Problem of the Day
Books A, B, C, and D are on the bookshelf.
A is between C and B. B is between A and
D. D is not on the right. What is the order
of the books from right to left?
D, B, A, C
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Sunshine State Standards
Prep for MA.7.S.6.2 Construct and
analyze…stem-and-leaf plots…
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Vocabulary
frequency table
cumulative frequency
stem-and-leaf plot
line plot
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
A frequency table is a way to organize
data into categories or groups.
By including a cumulative frequency column
in your table, you can keep a running total of
the frequencies in each category.
Remember!
The frequency of a data value is the
number of times it occurs.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 1: Organizing and Interpreting
Data in a Frequency Table
The list shows the average high temperatures for 20 cities
on one February day. Make a cumulative frequency table of
the data. How many cities had average high temperature
below 59 degrees?
69, 66, 65, 51, 50, 50, 44, 41, 38, 32, 32, 28, 20, 18, 12, 8,
8, 4, 2, 2
February Temperatures in 20 Cities
Step 1: Choose a
scale that includes
all of the data
values. Then
separate the scale
into equal intervals.
Average
Highs
0–19
20–39
40–59
60–79
Frequency
Cumulative
Frequency
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 1 Continued
The list shows the average high temperatures for 20 cities
on one February day. Make a cumulative frequency table of
the data. How many cities had average high temperature
below 59 degrees?
69, 66, 65, 51, 50, 50, 44, 41, 38, 32, 32, 28, 20, 18, 12, 8,
8, 4, 2, 2
Step 2: Find the
number of data
values in each
interval. Write
these numbers in
the “Frequency”
column.
February Temperatures in 20 Cities
Average
Frequency Cumulative
Frequency
Highs
40–59
7
5
5
60–79
3
0–19
20–39
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 1 Continued
The list shows the average high temperatures for 20 cities
on one February day. Make a cumulative frequency table of
the data. How many cities had average high temperature
below 59 degrees?
69, 66, 65, 51, 50, 50, 44, 41, 38, 32, 32, 28, 20, 18, 12, 8,
8, 4, 2, 2
Step 3: Find the
cumulative frequency
for each row by adding
all the frequency values
that are above or in
that row.
February Temperatures in 20 Cities
Average
Frequency Cumulative
Frequency
Highs
0–19
20–39
40–59
7
5
5
12
17
60–79
3
20
7
17 cities had average high temperature below 59 degrees.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 1
The list shows the grades received on an English exam.
Make a cumulative frequency table of the data. How many
students received a grade of 79 or below?
85, 84, 77, 65, 99, 90, 80, 85, 95, 72, 60, 66, 94, 86, 79,
87, 68, 95, 71, 96
Step 1: Choose a scale
that includes all of the
data values. Then
separate the scale into
equal intervals.
English Exam Grades
Grades
Frequency Cumulative
Frequency
60–69
70–79
80–89
90–99
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 1 Continued
The list shows the grades received on an English exam.
Make a cumulative frequency table of the data. How many
students received a grade of 79 or below?
85, 84, 77, 65, 99, 90, 80, 85, 95, 72, 60, 66, 94, 86, 79,
87, 68, 95, 71, 96
Step 2: Find
the number of
data values in
each interval.
Write these
numbers in the
“Frequency”
column.
English Exam Grades
Grades
Frequency Cumulative
Frequency
60–69
70–79
80–89
90–99
4
4
6
6
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 1 Continued
The list shows the grades received on an English exam.
Make a cumulative frequency table of the data. How many
students received a grade of 79 or below?
85, 84, 77, 65, 99, 90, 80, 85, 95, 72, 60, 66, 94, 86, 79,
87, 68, 95, 71, 96
Step 3: Find the
cumulative frequency
for each row by
adding all the
frequency values
that are above or in
that row.
English Exam Grades
Grades
Frequency Cumulative
Frequency
60–69
70–79
4
4
4
8
80–89
6
6
14
90–99
8 students received grades of 79 or below.
20
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
A stem-and-leaf plot uses the digits of each number
to organize and display a set of data. Each leaf on the
plot represents the right-hand digit in a data value,
and each stem represents the reamining left-hand
digits.
Stems
2
3
Leaves
4 7 9
0 6
Key: 2|7 means 27
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 2:
Organizing and Interpreting Data in a Stem-and-Leaf
Plot
The data shows the number of years coached by the top
15 coaches in the all-time NFL coaching victories. Make
a stem-and-leaf plot of the data. Then find the number
of coaches who coached fewer than 25 years.
33, 40, 29, 33, 23, 22, 20, 21, 18, 23, 17, 15, 15, 12, 17
Step 1: Order the data from least to greatest. Since
the data values range from 12 to 40, use tens digits
for the stems and ones digits for the leaves.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 2 Continued
The data shows the number of years coached by the top
15 coaches in the all-time NFL coaching victories. Make
a stem-and-leaf plot of the data. Then find the number
of coaches who coached fewer than 25 years.
33, 40, 29, 33, 23, 22, 20, 21, 18, 23, 17, 15, 15, 12, 17
Step 2: List the stems from least to greatest on the plot.
The stems
are the tens
digits.
Stems
1
2
3
4
Leaves
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 2 Continued
The data shows the number of years coached by the top
15 coaches in the all-time NFL coaching victories. Make
a stem-and-leaf plot of the data. Then find the number
of coaches who coached fewer than 25 years.
33, 40, 29, 33, 23, 22, 20, 21, 18, 23, 17, 15, 15, 12, 17
Step 3: List the leaves for each stem from least to greatest.
The stems
are the tens
digits.
Stems
1
2
3
4
Leaves
2 5 5 7 7 8
0 1 23 3 9
3 3
0
The leaves
are the
ones digits.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 2 Continued
Step 4: Add a key and a title.
Number of Years Coached
The stems
are the tens
Stems Leaves
digits.
Key: 2 | 1 means 21.
1
2
3
4
2 5 5 7 7 8
0 1 23 3 9
3 3
0
11 coaches coached fewer than 25 years.
The leaves
are the
ones digits.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 2
The list shows the number of times each soccer player
can bounce the ball on their knee. How many soccer
players can bounce the ball more than 36 times.
55, 60, 33, 30, 23, 45, 28, 41, 62, 29, 35, 40, 43, 37, 68,
30, 61, 27, 38, 41
Step 1: Order the data from least to greatest. Since the
data values range from 23 to 68, use tens digits
for the stems and ones digits for the leaves.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 2 Continued
The list shows the number of times each soccer player
can bounce the ball on their knee. How many soccer
players can bounce the ball more than 36 times.
55, 60, 33, 30, 23, 45, 28, 41, 62, 29, 35, 40, 43, 37, 68,
30, 61, 27, 38, 41
Step 2: List the stems from least to greatest on the plot.
The stems
are the
tens digits.
Stems
2
3
4
5
6
Leaves
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 2 Continued
The list shows the number of times each soccer player
can bounce the ball on their knee. How many soccer
players can bounce the ball more than 36 times.
55, 60, 33, 30, 23, 45, 28, 41, 62, 29, 35, 40, 43, 37, 68,
30, 61, 27, 38, 41
Step 3: List the leaves for each stem from least to greatest.
The stems
are the
tens digits.
Stems
2
3
4
5
6
Leaves
3 7 8 9
0 0 3 5 7 8
0 1 1 3 5
5
0 1 2 8
The leaves
are the
ones digits.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 2 Continued
Step 4: Add a key and a title.
Number of times a Soccer Player
can bounce the ball on their knee
Stems
2
The stems
are the tens
3
digits.
4
5
6
Key: 4 | 0 means 40.
Leaves
3 7 8 9
0 0 3 5 7 8
0 1 1 3 5
5
0 1 2 8
The leaves
are the ones
digits.
12 soccer players can bounce the ball on their knee
more than 36 times.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 3:
Organizing and Interpreting Data in a Line Plot
Make a line plot of the data. How many hours
per day did Morgan babysit most often?
Number of Babysitting Hours in July
M
T
W
Th
F
S
Su
Wk 1
0
6
4
6
5
8
2
Wk 2
2
7
7
7
0
6
8
Wk 3
0
6
8
5
6
1
2
Wk 4
4
8
4
3
3
6
0
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 3 Continued
Make a line plot of the data. How many hours
per day did Morgan babysit most often?
Step 1: The data values range from 0 to 8. Draw a
number line that includes this range.
0
1
2
3
4
5
6
7
8
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Additional Example 3 Continued
Make a line plot of the data. How many hours
per day did Morgan babysit most often?
Step 2: Put an X above the number on the number
line that corresponds to the number of babysitting
hours in July.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
2
3
4
5
6
7
8
The greatest number of X’s appear above the number 6.
This means that Morgan babysat most often for 6 hours.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Additional Example 3
Make a line plot of the data. How many slices
of pizza did most people eat?
Number of Slices Eaten per Person
2
4
1
2
5
3
1
0
4
3
2
5
3
2
4
6
1
4
2
2
5
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 3 Continued
Make a line plot of the data. How many slices
of pizza did most people eat?
Step 1: The data values range from 0 to 6. Draw a
number line that includes this range.
0
1
2
3
4
5
6
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Check It Out: Example 3 Continued
Make a line plot of the data. How many slices
of pizza did most people eat?
Step 2: Put an X above the number on the number
line that corresponds to the number slices of pizza
eaten per person.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
2
3
4
5
6
The greatest number of X’s appear above the number 2.
This means that most people ate 2 slices of pizza.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Lesson Quiz: Part I
The data shows the ages of some hospital nurses.
33, 35, 23, 39, 23, 24, 34, 21, 57, 45, 57, 60, 45,
24, 31, 42, 61, 45, 35, 38
1. Make a cumulative frequency table of the data. How
many of the nurses are under the age of 40? 12
Nurses’ Ages
Frequency
Cumulative
Frequency
20–29
5
5
30–39
40–49
7
4
12
16
50–59
2
18
60–69
2
20
Ages
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Lesson Quiz: Part II
The data shows the ages of some hospital nurses.
33, 35, 23, 39, 23, 24, 34, 21, 57, 45, 57, 60, 45,
24, 31, 42, 61, 45, 35, 38
2. Make a stem-and-leaf plot of the data. How many
nurses are over the age of 45? 4
Key: 4 | 2 means 42.
Nurses’ Ages
Stems Leaves
2
1 3 3 4 4
3
1 3 4 5 5 8 9
4
2 5 5 5
5
7 7
6
0 1
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Lesson Quiz: Part III
The data shows the ages of some hospital nurses.
33, 35, 23, 39, 23, 24, 34, 21, 57, 45, 57, 60, 45,
24, 31, 42, 61, 45, 35, 38
3. Make a line plot of the data. What age occurs most
often? 45
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
20-29
30-39
40-49
50-59
60-69
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Lesson Quiz for Student Response Systems
1. The data shows the number of loaves of bread a
bakery sold each day for a month. Identify a
cumulative frequency table of the data. How many
days did the bakery sell less than 30 loaves?
12, 19, 27, 24, 19, 44, 8, 32, 21, 37, 15, 6, 16,
48, 26, 5, 14, 23, 6, 35, 37, 28, 47, 40
A.
B.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Lesson Quiz for Student Response Systems
2. The data shows the ages (in days) of puppies in
a pet-care center. Identify a stem-and-leaf plot of
the data. How many puppies were over the age of
20 days?
24, 35, 29, 27, 38, 19, 7, 31, 28, 36, 22, 19, 12,
31, 6, 18, 33, 26, 15, 32, 23, 19, 5, 11, 4
A.
B.
Frequency Tables, Stem-and-Leaf
7-1 Plots, and Line Plots
Lesson Quiz for Student Response Systems
3. The data gives the shoe sizes of a group of
students. Identify a line plot of the data. What
shoe size occurs most often?
8, 8, 7, 6, 9, 9, 10, 13, 11, 10, 8, 9, 12, 10, 9, 9,
13, 12, 9, 8, 10, 7
A.
B.