1. Copyright © 2015, 2010, and 2007 Pearson Education, Inc. 1 Chapter 7 Data, Graphs, and Statistics

2. CHAPTER Copyright © 2015, 2010, and 2007 Pearson Education, Inc. 2 7 Data, Graphs, and Statistics 7.1Averages, Medians, and Modes 7.2Interpreting Data from Tables and Graphs 7.3Interpreting and Drawing Bar Graphs and Line Graphs 7.4Interpreting and Drawing Circle Graphs

3. OBJECTIVES Copyright © 2015, 2011, and 2008 Pearson Education, Inc. 3 7.4 Interpreting and Drawing Circle Graphs aExtract and interpret data from circle graphs. bDraw circle graphs.

4. Copyright © 2015, 2010, and 2007 Pearson Education, Inc. 4 A circle graph, also called a pie chart, are often used to show the percent of a quantity in each of several categories. Circle graphs can also be used very effectively to show visually the ratio of one category to another.

5. 5 Copyright © 2015, 2010, and 2007 Pearson Education, Inc. Example The following circle graph shows the favorite breakfast foods for students. a. What is the most popular item? b. What percent of the students favorite breakfast food is eggs and pancakes? cereal 20 + 11 = 31%

6. Copyright © 2015, 2010, and 2007 Pearson Education, Inc. 6 To draw a circle graph, or pie chart, think of a pie cut into 100 equally sized pieces. We would shade the appropriate size wedge for each item. Start with a circle marked in 100 equally spaced tick marks.

7. 7 Copyright © 2015, 2010, and 2007 Pearson Education, Inc. Example The results of a survey showing the percents of where people would most like to visit are given in the list to the right. Use this information to draw a circle graph. Yellowstone12% Hawaii58% Grand Canyon15% Golden Gate Bridge 8% Boston4% Disney World3%

8. 8 Copyright © 2015, 2010, and 2007 Pearson Education, Inc. continued We start with the 12% given for Yellowstone. We draw a line from the center to any tick mark. Then we count off 12 ticks and draw another line. We shade the wedge with the color and label the wedge as shown. Yellowstone12% Hawaii58% Grand Canyon15% Golden Gate Bridge8% Boston4% Disney World3%

9. 9 Copyright © 2015, 2010, and 2007 Pearson Education, Inc. continued To shade a wedge for Hawaii, at 58%, we start at one side of the Yellowstone wedge, count off 58 ticks, and draw another line. We shade the wedge with a different color and label the wedge.

10. Copyright © 2015, 2010, and 2007 Pearson Education, Inc. 10 Vacation Destinations We continue in this manner and choosing different colors, we obtain the graph shown here. Finally, we give the graph the overall title “Vacation Destinations”