1. Frequency Tables and Stem-and-Leaf Plots 1-3
Warm Up
Problem of the Day
Lesson Presentation
Course 2

2. 1-3 Frequency Tables and Stem-and-Leaf Plots Warm Up
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Warm Up
Use these numbers to answer the following questions.
136, 151, 104, 168, 140,
124, 162, 121, 118
1. What is the highest score?
2. What is the lowest score?
3. What is the range of scores?
4. How can you find the median?
168
104 64
Arrange the numbers in order and find the value in the middle.

3. 1-3 Frequency Tables and Stem-and-Leaf Plots
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Frequency Tables and Stem-and-Leaf 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
Course 2

4. 1-3 Frequency Tables and Stem-and-Leaf Plots
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Learn to organize and interpret data in frequency tables and stem-and-leaf plots.

5. Vocabulary 1-3 frequency table cumulative frequency stem-and-leaf plot
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Vocabulary
frequency table
cumulative frequency
stem-and-leaf plot

6. 1-3 Frequency Tables and Stem-and-Leaf Plots
Course 2
1-3
Frequency Tables and Stem-and-Leaf 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.

7. Additional Example 1: Organizing Data in a Frequency Table
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Additional Example 1: Organizing 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.
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
Average Highs
Frequency
Cumulative Frequency
Step 1: Look at the range to choose equal intervals for the data.
0–19
20–39
40–59
60–79

8. Additional Example 1 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf 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.
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
Average Highs
Frequency
Cumulative Frequency
0–19
20–39
40–59
60–79
Step 2: Find the number of data values in each interval. Write these numbers in the “Frequency” column. 7 5 5 3

9. Additional Example 1 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf 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.
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
Average Highs
Frequency
Cumulative Frequency
0–19
20–39
40–59
60–79 7 5 3
Step 3: Find the cumulative frequency for each row by adding all the frequency values that are above or in that row. 7 12 17 20

10. 1-3 Frequency Tables and Stem-and-Leaf Plots Try This: Example 1
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Try This: Example 1
The list shows the grades received on an English exam. Make a cumulative frequency table of the data.
85, 84, 77, 65, 99, 90, 80, 85, 95, 72, 60, 66, 94, 86, 79, 87, 68, 95, 71, 96
English Exam Grades
Grades
Frequency
Cumulative Frequency
Step 1: Look at the range to choose equal intervals for the data.
60–69
70–79
80–89
90–99

11. Try This: Example 1 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Try This: Example 1 Continued
The list shows the grades received on an English exam. Make a cumulative frequency table of the data.
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

12. Try This: Example 1 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Try This: Example 1 Continued
The list shows the grades received on an English exam. Make a cumulative frequency table of the data.
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
80–89
90–99 4 6 4 8 14 20

13. 1-3 Frequency Tables and Stem-and-Leaf Plots
Course 2
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Frequency Tables and Stem-and-Leaf Plots
A stem-and-leaf plot can be used to show how often data values occur and how they are distributed. Each leaf on the plot represents the right-hand digit in a data value, and each stem represents left-hand digits.
Stems Leaves
Key: 2|7 means 27

14. Additional Example 2: Organizing Data in a Stem-and-Leaf Plot
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Additional Example 2: Organizing 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.
33, 40, 29, 33, 23, 22, 20, 21, 18, 23, 17, 15, 15, 12, 17
Step 1: Find the least data value
and the greatest data value.
Since the data values range from 12 to 40, use tens digits for the stems and ones digits for the leaves.

15. Additional Example 2 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf 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.
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.
Stems Leaves
The stems are the tens digits. 1 2 3 4

16. Additional Example 2 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf 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.
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.
Stems Leaves
The stems are the tens digits.
The leaves are the ones digits. 2 5 5 7 7 8 1 2 3 4 1 2 3 3 9 3 3

17. Additional Example 2 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf 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.
33, 40, 29, 33, 23, 22, 20, 21, 18, 23, 17, 15, 15, 12, 17
Step 4: Add a key and a title.
Stems Leaves 1 2 3 4 5 7 8 9
Number of Years Coached
The stems are the tens digits.
The leaves are the ones digits.
Key: 2 | 1 means 21.

18. 1-3 Frequency Tables and Stem-and-Leaf Plots Try This: Example 2
Course 2
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Frequency Tables and Stem-and-Leaf Plots
Try This: Example 2
The list shows the number of students on twenty school buses.
55, 60, 33, 30, 23, 45, 28, 41, 62, 29, 35, 40, 43, 37, 68, 30, 61, 27, 38, 41
Step 1: Find the least data value
and the greatest data value.
Since the data values range from 23 to 68, use tens digits for the stems and ones digits for the leaves.

19. Try This: Example 2 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Try This: Example 2 Continued
The list shows the number of students on twenty school buses.
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.
Stems Leaves
The stems are the tens digits. 2 3 4 5 6

20. Try This: Example 2 Continued
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Try This: Example 2 Continued
The list shows the number of students on twenty school buses.
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.
Stems Leaves 2 3 4 5 6
The stems are the tens digits.
The leaves are the ones digits. 3 7 8 9 3 5 7 8 1 1 3 5 5 1 2 8

21. Number of Students on School Buses
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Try This: Example 2 Continued
The list shows the number of students on twenty school buses.
55, 60, 33, 30, 23, 45, 28, 41, 62, 29, 35, 40, 43, 37, 68, 30, 61, 27, 38, 41
Step 4: Add a key and a title.
Number of Students on School Buses
The stems are the tens digits.
Stems Leaves 2 3 4 5 6 7 8 9 1
The leaves are the ones digits.
Key: 4 | 0 means 40.

22. 1-3 Frequency Tables and Stem-and-Leaf Plots Lesson Quiz
Course 2
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Frequency Tables and Stem-and-Leaf Plots
Lesson Quiz
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.
2. Make a stem-and-leaf plot of the data.

23. 1-3 Frequency Tables and Stem-and-Leaf Plots Lesson Quiz
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Lesson Quiz
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.
Nurses’ Ages
Ages
Frequency
Cumulative Frequency
20–
30–
40–
50–
60–

24. 1-3 Frequency Tables and Stem-and-Leaf Plots Lesson Quiz Nurses’ Ages
Course 2
1-3
Frequency Tables and Stem-and-Leaf Plots
Lesson Quiz
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.
Stems Leaves 2 3 4 5 6
7 7
0 1
Nurses’ Ages
Key: 4 | 2 means 42.