1. Bar Graphs Line Plots Frequency Tables Histograms
Lessons 6.4 and 6.5
Bar Graphs
Line Plots
Frequency Tables
Histograms

2. Learn to display and analyze data in bar graphs.
Learn to organize data in line plots, frequency tables, and histograms.

3. Vocabulary bar graph double-bar graph frequency frequency table
line plot
histogram

4. A bar graph can be used to display and compare data
A bar graph can be used to display and compare data. A bar graph displays data with vertical or horizontal bars.

5. Example 1: Reading a Bar Graph
Use the bar graph to answer each question.
Which biome in the graph has the least average summer temperature?
Find the lowest bar.
The coniferous forest has the least average summer temperature.

6. Example 1B: Reading a Bar Graph
Use the bar graph to answer each question.
Which biomes in the graph have an average summer temperature of 30C or greater?
Find the bar or bars whose heights measure 30 or more than 30.
The grassland and the rain forest have average summer temperatures of 30C or greater.

7. Use the data to make a bar graph.
White board practice:
Use the data to make a bar graph.
285
215
310
Grade 8
Grade 7
Grade 6
Tickets Sold

8. White board practice: Solution
Use the data to make a bar graph.
Step 1:Find an appropriate scale and interval. The scale must include all of the data values. The interval separates the scale into equal parts.
285
215
310
Grade 8
Grade 7
Grade 6
Tickets Sold
Grade 6
Grade 7
Grade 8
Tickets Sold
Grade
Tickets
Step 2:Use the data to determine the lengths of the bars. Draw bars of equal width. The bars cannot touch.
Step 3: Title the graph and label the axes.

9. A double-bar graph shows two sets of related data.

10. Understand the Problem
Example 2: Problem Solving Application
Make a double-bar graph to compare the data in the table. 4 14 8
Girls 16 6 12
Boys
Science
Music
Art
Club
Club Memberships
Understand the Problem
You are asked to use a graph to compare the data given in the table. You will need to use all of the information given.

11. Example 2 Continued
Determine appropriate scales for both sets of data.
Use the data to determine the lengths of the bars. Draw bars of equal width. Bars should be in pairs. Use a different color for boy memberships and girl memberships. Title the graph and label both axes.
Include a key to show what each bar represents.

12. Understand the Problem
White board practice:
Make a double-bar graph to compare the data in the table. 15 7 11
Girls 16 14 9
Boys
Year Book
Chess
Band
Club
Club Memberships
Understand the Problem
You are asked to use a graph to compare the data given in the table. You will need to use all of the information given.

13. White board practice: Solution
Determine appropriate scales for both sets of data.
Use the data to determine the lengths of the bars. Draw bars of equal width. Bars should be in pairs. Use a different color for boy memberships and girl memberships. Title the graph and label both axes.
Include a key to show what each bar represents.
Club Memberships
Memberships
Club

14. The frequency of a data value is the number of times it occurs.
A frequency table tells the number of times an event, category, or group occurs.

15. Example 3: Using Tally Marks to Make a Frequency Table
Students in Mr. Ray’s class recorded their fingerprint patterns. Which type of pattern do most students in Mr. Ray’s class have?
whorl loop whorl loop
arch arch loop whorl
loop arch whorl arch
arch whorl arch loop
Make a table to organize the data.

16. Number of Fingerprint Patterns
Students in Mr. Ray’s class recorded their fingerprint patterns. Which type of pattern do more students in Mr. Ray’s class have?
whorl loop whorl loop
arch arch loop whorl
loop arch whorl arch
arch whorl arch loop
Step 1: Make a column for each fingerprint pattern.
Step 2: For each fingerprint, make a tally mark in the appropriate column.
Loop
Arch
Whorl
Number of Fingerprint Patterns
Most students in Mr. Ray’s class have an arch fingerprint.
l l l l l l l l l l l l l

17. Make a table to organize the data.
White board practice:
Students in Ms. Gracie’s class recorded their fingerprint patterns. Which type of pattern do more students in Ms. Gracie’s class have?
whorl loop whorl loop
arch whorl loop whorl
loop whorl whorl arch
arch whorl arch loop
Make a table to organize the data.

18. Number of Fingerprint Patterns
White board practice: Solution
Students in Ms. Gracie’s class recorded their fingerprint patterns. Which type of pattern do more students in Ms. Gracie’s class have?
whorl loop whorl loop
arch whorl loop whorl
loop whorl whorl arch
arch whorl arch loop
Step 1: Make a column for each fingerprint pattern.
Step 2: For each fingerprint, make a tally mark in the appropriate column.
Loop
Arch
Whorl
Number of Fingerprint Patterns
Most students in Ms. Gracie’s class have a whorl fingerprint.
l l l l l l l l l l l l l l

19. A line plot uses a number line and x’s or other symbols to show frequencies of values.

20. Example 4: Making a Line Plot
Students collected tennis balls for a project. The number of balls collected by the students is recorded in the table. Make a line plot of the data. 11 10 15 14 16
Tennis Balls Collected
Step 1: Draw a number line.
x x x x
x x x
x x
x x
Step 2: For each tennis ball, use an x on the number line to represent how many were collected. x

21. White board practice:
Students collected aluminum cans for a project. The number of cans collected by the students is recorded in the table. Make a line plot of the data. 11 15 5 14 7
Cans Collected

22. Write board Practice: Solution
Students collected aluminum cans for a project. The number of cans collected by the students is recorded in the table. Make a line plot of the data. 11 15 5 14 7
Cans Collected
Step 1: Draw a number line.
x x x
x x x
x x x
Step 2: For each aluminum can, use an x on the number line to represent how many were collected. x x

23. Pages Read Last Weekend
Example 5: Making a Frequency Table w/ Intervals
Use the data in the table to make a frequency table with intervals. 18 37 34 22 5 7 19 40 15 12
Pages Read Last Weekend

24. Pages Read Last Weekend
Example 5 Continued
Use the data in the table to make a frequency table with intervals
Frequency
31–40
21–30
11–20
1–10
Number
Pages Read Last Weekend
Step 1: Choose equal intervals.
Step 2: Find the number of data values in each interval. Write these numbers in the “Frequency” row.
This table shows that 2 students read between 1 and 10 pages, 4 students read between 11 and 20 pages, 1 person read between 21 and 30 pages, and 3 people read between 31 and 40 pages last weekend.

25. Number of Miles Driven on Saturday
White board practice:
Use the data in the table to make a frequency table with intervals. 38 21 34 27 5 7 19 9 29 17
Number of Miles Driven on Saturday

26. Number of Miles Driven on Saturday
White board practice: Solution
Use the data in the table to make a frequency table with intervals.
Frequency
31–40
21–30
11–20
1–10
Number
Number of Miles Driven on Saturday
Step 1: Choose equal intervals.
Step 2: Find the number of data values in each interval. Write these numbers in the “Frequency” row.
This table shows that 3 people drove between 1 and 10 miles, 2 people drove between 11 and 20 miles, 3 people drove between 21 and 30 miles, and 2 people drove between 31 and 40 miles on Saturday.

27. A histogram is a bar graph that shows the number of data items that occur within each interval.

28. Pages Read Last Weekend
Example 6: Making a Histogram
Use the frequency table in Example 5 to make a histogram.
Frequency
31–40
21–30
11–20
1–10
Number
Pages Read Last Weekend
Step 1: Choose an appropriate scale and interval.
Step 2: Draw a bar for the number of students in each interval. The bars should touch but not overlap.
Step 3: Title the graph and label the axes.

29. Number of Miles Driven on Saturday
White board practice:
Use the frequency table from your last white board practice to make a histogram.
Frequency
31–40
21–30
11–20
1–10
Number
Number of Miles Driven on Saturday

30. Number of Miles Driven on Saturday Number Miles Driven on Saturday
White board practice: Solution
Use the frequency table from your last white board practice to make a histogram.
Frequency
31–40
21–30
11–20
1–10
Number
Number of Miles Driven on Saturday
Number Miles Driven on Saturday
Number of Miles
People
Step 1: Choose an appropriate scale and interval.
Step 2: Draw a bar for the number of students in each interval. The bars should touch but not overlap.
Step 3: Title the graph and label the axes.

31. Lesson Quiz:
1. Students listed the number of days they spent on vacation in one year. Make a tally table with intervals of 5.
2, 18, 5, 15, 7, 10, 1, 10, 4,
16, 7, 11, 17, 3, 8, 14, 13, 10

32. Use the bar graph to answer each question.
2. Which animal was least popular among students?
3. Which pet was more popular to twice as many students as rabbits were?
Student Pet Survey
bird
dog

33. 4. Use your tally table from problem 1 to make a frequency table.

34. 5. Richard listed the number of books lent by their school library each day. Create a tally table with intervals of 5.
3, 18, 6, 14, 8, 10, 1, 10, 4, 17, 8, 11, 17, 4, 8, 14, 14, 10

35. 2. Create a frequency table for the given data.