Does your school have a mascot? Well, look at this situation about mascots.
Casey's school is going to decide on a new mascot for the football team. To figure out which animal will be the most popular, the student council conducted a survey. This is the graph of the results.
Casey was hoping that the eagle would be chosen as the mascot. Is that what this circle graph shows?
Based on this circle graph, which animal will be chosen?
This Concept is all about interpreting circle graphs. You may already know the answer to these questions, but you will learn more about interpreting circle graphs in this Concept.
Guidance
A circle graph is a visual way of displaying data that is written in percents. The circle of a circle graph represents 100%. The parts of the whole that the items being graphed represent are shown in pie shaped wedges. Each wedge shows what part of 100 that item represents.
This is a graph of data about a student’s spending habits. You may remember seeing this circle graph in an earlier Concept. Here is the data on the graph.
Savings = 50%
Baseball Cards = 10%
Food = 40%
By looking at the circle graph, we can see that out of 100 % of his money, this student saves half (or 50%). He spends a small fraction on baseball cards and the rest is spent on food.
Notice that all three percents add up to 100%.
A circle graph shows information out of 100.
Now answer these questions about circle graphs.
Example A
Looking at the graph above, what percent is not spent on saving?
Solution:
Example B
True or False. The following percents could be part of one circle graph: 25%, 10% and 65%.
Solution: True, because the percents add up to 100.
Example C
True or false. The following percents could be part of the same circle graph: 35%, 70% and 5%.
Solution: False, because they add up to more than 100.
Here is the original problem once again.
Casey's school is going to decide on a new mascot for the football team. To figure out which animal will be the most popular, the student council conducted a survey. This is the graph of the results.
Casey was hoping that the eagle would be chosen as the mascot. Is that what this circle graph shows?
Based on this circle graph, which animal will be chosen?
If you look carefully at this circle graph, the eagle is not the largest section of the graph. Since each graph shows a percent of a whole, the eagle did not receive enough votes.
According to this graph, the cougar is the most popular. It will be chosen as the new mascot.
Vocabulary
- Percent
- Percent means out of 100. It is a quantity written with a % sign.
- Fraction
- A fraction is a part of a whole. A fraction is written mathematically as one value on top of another, separated by a fraction bar. It is also called a rational number .
- Decimal
- It is a part of a whole. The numbers to the left of the decimal point represent whole quantities. The numbers to the right of the decimal point represent parts.
- Circle Graph
- It is a visual display of data that uses percentages and circles.
Guided Practice
Here is one for you to try on your own.
Based on this graph, which foreign language is the most popular?
Answer
Spanish has the largest section of the graph with 55%. This is the most popular subject.
This is our answer.
Video Review
Here is a video for review.
Khan Academy: Reading Pie Graphs (Circle Graphs)
Explore More
Directions: Use each circle graph to answer the following questions.
1. Which foreign language is the least popular?
2. If 30% of the students chose French, what percent did not choose French?
3. What percent of the students chose Italian?
4. What percent of the students did not chose Italian?
5. What percent of the students chose Latin?
6. What percent of the students did not choose Latin or French?
7. What percent of the students did not choose French or Spanish?
8. What percent of the students did not choose German?
9. What percent of Patrick's budget is spent of transportation?
10. What percent of the budget is spent on food?
11. What percent of the budget is not spent on food or savings?
12. If 35% of the budget is spent on rent and utilities, what percent is not spent on this?
13. True or false. Patrick does not spend any money on clothing.
14. What percent is spent on savings and food together?
15. If Patrick was going to increase his savings by 15% what would the new percent of savings be?