Modeling: Circle Graphs

These web-based activities were developed, during summer sessions from 1997 through 1999, by students at Mainland High School, located in Daytona Beach, FL. As part of Mainland's CCTT grant, the students were given permission by the book's publisher to convert the ancillary materials of the County's adopted Algebra 1 textbook (Glencoe Algebra 1 — ISBN: 9780028253282) into html format.

Modeling:
Circle Graphs

Information can also be displayed using a circle graph. A whole circle shows the entire amount or 100% of the given data. The circle is divided into sections or sectors that show the fractional or percentage parts.

For a school project Jeff records the types of vehicles that pass by his house during one day. From this information he makes the following circle graph.

If 2,500 vehicles pass by Jeff's house, how many are pick-up trucks?

From the graph you can see that 5% of the vehicles are pick-up trucks.

So find 5% of 2,500

0.05 x 2,500 =125

During the day 125 pick-up trucks pass Jeff's house.

Use the circle graph above. Find the number of compact cars that pass Jeff's house.

Use the graph above for Exercises 1 - 5.

1. Find the number of sedans that pass Jeff's house.	5. An automobile insurance company estimates that a total of 3,000 vehicles will pass by Jeff's house next year. The percentages for each type of vehicle shown on the circle graph is expected to remain the same. How many vans will pass by Jeff's house next year? How many compact cars will pass by Jeff's house next year? How many more vans will pass by Jeff's house next year than this year?
2. Find the number of vans that pass Jeff's house.
3. Find the number of trucks that pass Jeff's house.
4. How many more compact cars pass by Jeff's house than pick-up trucks?