Have you ever collected survey data? Take a look at this dilemma.
Thirty-five girls and thirty-five boys were asked to state their favorite sport. The results of the survey are displayed on the graph below. You can make several inferences studying the graph “Favorite Sports.”
Here is a bar graph to show the data.
What conclusions can you draw by examining this data?
Use this Concept to learn about multiple bar graphs. When finished, you will be able to look at this bar graph and draw conclusions.
Guidance
A multiple bar graph is similar to a bar graph, but depicts two or three pieces of information for each item on the horizontal \begin{align*}(x)\end{align*} axis, rather than one.
A double bar graph may be used to compare the survey answers of one group verses another group. A triple bar graph may be used to compare data recorded over a three day period or over several days.
Frank’s Farm Stand kept track of the number of pounds of vegetables sold over a three-day period. The results are listed on the table below. Create a multiple bar graph to display and compare the amounts of vegetables sold over the three day period.
Type of Vegetable: | Pounds Sold: Day One | Pounds Sold: Day Two | Pounds Sold: Day Three |
---|---|---|---|
Squash | 32 lbs. | 36 lbs. | 36 lbs. |
Zucchini | 40 lbs. | 33 lbs. | 37 lbs. |
Corn | 56 lbs. | 65 lbs. | 67 lbs. |
Carrots | 28 lbs. | 25 lbs. | 23 lbs. |
Romaine Lettuce | 27 lbs. | 31 lbs. | 34 lbs. |
Tomatoes | 44 lbs. | 54 lbs. | 58 lbs. |
To create a multiple bar graph:
- Draw the horizontal \begin{align*}(x)\end{align*} and vertical \begin{align*}(y)\end{align*} axis.
- Give the graph the title “Frank’s Farm Stand.”
- Label the horizontal axis “Vegetables.”
- Label the vertical axis “Pounds Sold.”
- Look at the range in data and decide how the units on the vertical axis \begin{align*}(y)\end{align*} should be labeled. In this case, label the vertical axis 0 - 80 by tens.
- For each vegetable on the horizontal \begin{align*}(x)\end{align*} axis, draw a vertical column to the appropriate value three times, one column representing day one, a second column for day two, and a third column for day three.
- Choose three colors, one to represent the values for day one, one for the values for day two, and finally one to represent the values for day three.
You can also draw conclusions about data from multiple bar graphs. These comparisons can help you to discover patterns and trends about statistics.
Looking at the bar graph “Frank’s Farm Stand Sales,” what can you infer about the difference in sales over the three day period?
It is apparent that sales of squash, corn, romaine lettuce, and tomatoes increased over the three day period. Zucchini sales dropped on day two, but increased on day three. However, carrot sales declined on day two and again on day three. Note that the same amount of carrots and romaine lettuce were sold on day one.
Taylor created a table to compare the amount of gravitational pull on each planet compared to that on Earth. Create a multiple bar graph to display the information from Taylor’s chart.
Planet Name: | Planet’s Gravitational Pull: | Earth’s Gravitational Pull: |
---|---|---|
Mercury | 0.38 m/s | 1.0 m/s |
Venus | 0.91 m/s | 1.0 m/s |
Mars | 0.38 m/s | 1.0 m/s |
Jupiter | 2.54 m/s | 1.0 m/s |
Saturn | 0.93 m/s | 1.0 m/s |
Uranus | 0.8 m/s | 1.0 m/s |
Neptune | 1.2 m/s | 1.0 m/s |
To create a multiple bar graph:
- Draw the horizontal \begin{align*}(x)\end{align*} and vertical \begin{align*}(y)\end{align*} axis.
- Give the graph the title “Planet’s Gravitational Pull.”
- Label the horizontal axis “Planets.”
- Label the vertical axis “Gravitational Pull.”
- Look at the range in data and decide how the units on the vertical axis \begin{align*}(y)\end{align*} should be labeled. In this case, label the vertical axis 0-3 by 0.5.
- For each planet on the horizontal \begin{align*}(x)\end{align*} axis, draw a vertical column to the appropriate value. For example, the vertical column should reach 0.38 for Mercury to show its gravitational pull.
- Next to each vertical column for each planet, draw a vertical column that reaches 1.0 to represent the gravitational pull on Earth.
- Choose two colors, one to represent the values for each planet and another to represent the value for Earth.
Looking at the double bar graph “Planet’s Gravitational Pull,” what can you infer about each planet?
This graph compares the gravitational pull on Earth with the other seven major planets. You can see that with the exception of Jupiter and Neptune, all planets have a gravitational pull less than that of Earth. You can see that Mercury and Mars both have a gravitational pull of 0.38 m/s. It is apparent that Venus and Saturn are the planets with a gravitational pull that is closest to that of Earth.
Write down the steps to creating multiple bar graphs in your notebook.
Now use the graph on planets to answer the following questions.
Example A
Which planet has the greatest difference between the earth's gravitational pull and the planet's gravitational pull?
Solution: Jupiter
Example B
What is the measurement of the earth's gravitational pull for Saturn?
Solution: \begin{align*}1\end{align*}
Example C
Which has the greatest planet gravitational pull, Neptune or Pluto?
Solution: Neptune
Here is the original problem once again.
Thirty-five girls and thirty-five boys were asked to state their favorite sport. The results of the survey are displayed on the graph below. You can make several inferences studying the graph “Favorite Sports.”
Here is a bar graph to show the data.
What conclusions can you draw by examining this data?
You can see that soccer was the favorite sport among girls and track was the least favorite. More boys preferred basketball than any other choice. Equal numbers of boys and girls stated that their favorite sport was baseball.
Vocabulary
- Bar Graph
- a graph designed to compare data and show the frequency of the data.
- Multiple Bar Graph
- a graph the shows how different strands of data is compared over time. It shows the frequency of this data and compares it at the same time.
Guided Practice
Here is one for you to try on your own.
Look at this bar graph once again.
November's ice cream sales were half of the October sales for Week's 1, 2, 3 and 4.
Given this information, what were the sales for each of these weeks?
Answer
To figure this out, we will need to read the bar graph.
Here are the October sales.
Week 1 = 400
Week 2 = 200
Week 3 = 100
Week 4 = 100
Which means the sales for November were the following:
Week 1 = 200
Week 2 = 100
Week 3 = 50
Week 4 = 50
Video Review
This is a Khan Academy video on reading bar graphs. This is a supporting video for this Concept.
Practice
Directions: The multiple bar graph below depicts the number of Major League Baseball teams in each state, as well as the number of World Series Championships won by each state. Use the graph to answer the questions.
1. How many Major League Baseball teams are represented on the graph? _____
2. How many World Championships are represented on the graph? _____
3. How many of states on the graph have won a Major League Championship? _____
4. Which states have equal numbers of Major League Baseball teams? _____
5. Which state has won the greatest number of World Championships? _____
Directions: Twenty students in \begin{align*}6^{th}\end{align*}, \begin{align*}7^{th}\end{align*}, and \begin{align*}8^{th}\end{align*} grade were asked to state how many of each of the following electronic devices their homes contained.
6. Create a multiple line graph to display the information from the table.
Name of Device: | \begin{align*}6^{th}\end{align*} Grade Answers: | \begin{align*}7^{th}\end{align*} Grade Answers: | \begin{align*}8^{th}\end{align*} Grade Answers: |
---|---|---|---|
Television | 35 | 28 | 31 |
DVD Player | 30 | 28 | 20 |
Computer | 19 | 20 | 17 |
Game System | 15 | 14 | 20 |
Video Camera | 14 | 17 | 12 |
7. What is the most common electronic device in the sixth grade?
8. What is the most common electronic device in the seventh grade?
9. What is the most common electronic device in the eighth grade?
10. What is the least common electronic device in the sixth grade?
11. What is the least common electronic device in the seventh grade?
12. What is the least common electronic device in the eighth grade?
13. What is the difference between the number of sixth graders who watch tv and the number of seventh graders?
14. What is the difference between the number of seventh graders who watch tv and the number of eighth graders?
15. True or false. For computer use, seventh graders have the highest number.