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Bar Graphs Unit 11 > Lesson 3 of 10


Example 1:  A survey of students' favorite after-school activities was conducted at a school. The table below shows the results of this survey.
Students' Favorite After-School Activities
Activity Number of Students
Play Sports 45
Talk on Phone 53
Visit With Friends 99
Earn Money 44
Chat Online 66
School Clubs 22
Watch TV 37
Note that since the data in this table is not changing over time, a line graph would not be a good way to visually display this data. Each quantity listed in the table corresponds to a particular category. Accordingly, the data from the table above has been displayed in the bar graph below.

A bar graph is useful for comparing facts. The bars provide a visual display for comparing quantities in different categories. Bar graphs help us to see relationships quickly. Another name for a bar graph is a bar chart. Each part of a bar graph has a purpose.

title The title tells us what the graph is about.
labels The labels tell us what kinds of facts are listed.
bars The bars show the facts.
grid lines Grid lines are used to create the scale.
categories Each bar shows a quantity for a particular category.

Now that we have identified the parts of a bar graph, we can answer some questions about the graph in Example 1.

QUESTION ANSWER
1. What is the title of this bar graph?    Students' Favorite After-School Activities
2. What is the range of values on the (horizontal) scale? 0 to 100
3. How many categories are in the graph?    7
4. Which after-school activity do students like most? Visit With Friends
5. Which after-school activity do students like least? School Clubs
6. How many students like to talk on the phone? 53
7. How many students like to earn money? 44
8. Which two activities are liked almost equally? Play Sports and Earn Money
9. List the categories in the graph from greatest to least. Visit With Friends, Online, Talk on Phone, Play Sports, Earn Money, Watch TV, School Clubs.


Example 2: Students in a class voted on their favorite fruit. Each student voted once. The bar graph below summarizes the data collected from the class vote.

QUESTION ANSWER
1. What is the range of values on the (horizontal) scale? 0 to 5
2. How many categories are in the graph?  6
3. Which fruit had the most votes? Apples
4. Which fruit had the least votes? Pears
6. How many students voted for bananas? 3
7. How many students voted for grapes? 2
8. Which two fruits had the same number of votes? Oranges and Strawberries
9. List the categories in the graph from least to greatest. Pears, Grapes, Bananas, Oranges, Strawberries, Apples.


The bar graphs in Examples 1 and 2 each have horizontal bars. It is also possible to make a bar graph with vertical bars. You can see how this is done in Example 3 below.

Example 3: The amount of sugar in 7 different foods was measured as a percent  The data is summarized in the bar graph below.

QUESTION ANSWER
1. What is the title of this bar graph?    Amount of Sugar in Certain Foods
2. What is the range of values on the (vertical) scale? 0 to 35
3. How many categories are in the graph? 7
4. Which food had the highest percentage of sugar? Chocolate Bar
5. Which food had the lowest percentage of sugar? Ketchup
6. What percentage of sugar is in soda? 28.9%
7. What is the difference in percentage of sugar between ice cream and crackers? 21.4 - 11.8 = 9.6%


Summary:   A bar graph is useful for comparing facts. The bars provide a visual display for comparing quantities in different categories. Bar graphs help us to see relationships quickly. Bar graphs can have horizontal or vertical bars. Another name for a bar graph is a bar chart.

Exercises

Directions: Refer to the bar graph below to answer each question. For each exercise below, click once in the ANSWER BOX, type in your answer and then click ENTER. Your answer should be given as a word or as a  whole number. After you click ENTER, a message will appear in the RESULTS BOX to indicate whether your answer is correct or incorrect. To start over, click CLEAR.


Students in Mrs. Glosser's class were surveyed about snacks and asked to choose the one snack food they liked most from a list. The bar graph below summarizes the data collected from this survey.


1. Which snack was preferred most?
ANSWER BOX:  

RESULTS BOX:


2. Which snack was preferred by 2 students?

ANSWER BOX:  

RESULTS BOX:


3. How many students preferred pretzels?
ANSWER BOX:  

RESULTS BOX:


4. Which snack was preferred by 3 students?
ANSWER BOX:  

RESULTS BOX:


5. According to the graph, what value corresponds to the number of students who preferred fruit and vegetables equally?
ANSWER BOX:  

RESULTS BOX:



This lesson is by Gisele Glosser. You can find me on Google.

Lessons on Data and Graphs
Data and Line Graphs
Constructing Line Graphs
Data and Bar Graphs
Constructing Bar Graphs
Data and Circle Graphs
Constructing Circle Graphs
Comparing Graphs
Practice Exercises
Challenge Exercises
Solutions

Related Activities
Interactive Puzzles
Printable Worksheets
Math and Sports WebQuests

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