766 CHAPTER 12 Statistics $1 This year $2 Next year Figure 12.5 100 100 80 60 40 20 0 95 2023 2024 2023 2024 (a) (b) Figure 12.3 $1 This year $2 Next year Figure 12.4 Research 49% Use e-mail 37% Gather information about products and services 42% Surf for new sites 16% Check for news, weather updates 15% Purchase goods and services 24% Why People Surf the Web Top six reasons Americans say they use the Internet Figure 12.6 The graph in Fig. 12.6 is an example of a circle graph. We will discuss circle graphs further in Section 12.2. In a circle graph, the total circle represents 100%. Therefore, the sum of the parts should add up to 100%. This graph is misleading, since the sum of its parts is 183%. A graph other than a circle graph should have been used to display the top six reasons Americans say they use the Internet. Despite the examples presented in this section, you should not be left with the impression that statistics is used solely for the purpose of misleading or cheating the consumer. As stated earlier, there are many important and necessary uses of statistics. Most statistical reports are accurate and useful. You should realize, however, the importance of being an aware consumer. graphs, which stock would you purchase? Actually, the two graphs present identical information; the only difference is that the vertical scale of the graph for stock B has been exaggerated. The two graphs in Fig. 12.3 show the same change. However, the graph in part (a) appears to show a greater increase than the graph in part (b), again because of a different scale. Consider a claim that if you invest $1, by next year you will have $2. This type of claim is sometimes misrepresented, as in Fig. 12.4. Actually, your investment has only doubled, but the area of the square on the right is four times that of the square on the left. By expressing the amounts as cubes (Fig. 12.5), you increase the volume eightfold. Instructor Resources for Section 12.1 in MyLab Math • Objective-Level Videos 12.1 • PowerPoint Lecture Slides 12.1 • MyLab Exercises and Assignments 12.1
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