Copyright © 2009 Pearson Education, Inc. 3.3 Graphics in the Media LEARNING GOAL Understand how to interpret the many types of more complex graphics that are commonly found in news media. Page 112 Copyright © 2009 Pearson Education, Inc.

Copyright © 2009 Pearson Education, Inc. Multiple Bar Graphs and Line Charts A multiple bar graph is a simple extension of a regular bar graph: It has two or more sets of bars that allow comparison between two or more data sets. All the data sets must have the same categories so that they can be displayed on the same graph. Page 113 Figure 3.18 A multiple bar graph. Source: Wall Street Journal Almanac. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 2

Copyright © 2009 Pearson Education, Inc. A multiple line chart follows the same basic idea as a multiple bar chart, but shows the related data sets with lines rather than bars. Page 113 Figure 3.19 A multiple line chart. Source: New York Times. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 3

Copyright © 2009 Pearson Education, Inc. EXAMPLE 1 Reading the Investment Graph Consider Figure 3.19 (previous slide). Suppose that, on July 7, you had invested $100 in a stock fund that tracks the S&P 500, $100 in a bond fund that follows the Lehman Index, and $100 in gold. If you sold all three funds on September 15, how much would you have gained or lost? Solution: The graph shows that the $100 in the stock fund would have been worth about $105 on September 15. The $100 bond investment would have declined in value to about $99. The gold investment would have held its initial value of $100. On September 15, your complete portfolio would have been worth $105 + $99 + $100 = $304 You would have gained $4 on your total investment of $300. Pages 113-114. Figure 3.19 is on the previous slide. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 4

Copyright © 2009 Pearson Education, Inc. EXAMPLE 2 Graphic Conversion Figure 3.20 is a multiple bar graph of the numbers of U.S. households with computers and the number of on-line households. Redraw this graph as a multiple line chart. Briefly discuss the trends shown on the graphs. Pages 114-115 Figure 3.20 A multiple bar graph of trends in home computing. Source: Statistical Abstract of the United States. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 5

Copyright © 2009 Pearson Education, Inc. EXAMPLE 2 Graphic Conversion Solution: To convert the graphic to a multiple line chart, we must change the two sets of bars to a set of two lines. We place a dot corresponding to the height of each bar in the center of each category (year) and then connect the dots of the same color with a color-coded line, as shown in Figure 3.21. Pages 114-115 Figure 3.21 Multiple line chart showing the data from Figure 3.20. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 6

Copyright © 2009 Pearson Education, Inc. EXAMPLE 2 Graphic Conversion Figure 3.21 Multiple line chart showing the data from Figure 3.20. Solution: (cont.) The most obvious trend is that both data sets show an increase with time. We see a second trend by comparing the bars within each year. In 1995, the number of on-line homes (about 10 million) was less than one-third the number of homes with computers (about 33 million). Pages 114-115 Copyright © 2009 Pearson Education, Inc. Slide 3.3- 7

Copyright © 2009 Pearson Education, Inc. EXAMPLE 2 Graphic Conversion Figure 3.21 Multiple line chart showing the data from Figure 3.20. Solution: (cont.) By 2003, the number of on-line homes (about 62 million) was about 90% of the number of homes with computers (about 70 million). This tells us that a higher percentage of computer users are going on-line. If we project the trends into the future, it seems likely that the number of on-line households will approach the number of households with computers, and both will approach the total number of households in the United States. Pages 114-115 Copyright © 2009 Pearson Education, Inc. Slide 3.3- 8

Copyright © 2009 Pearson Education, Inc. Stack Plots Another way to show two or more related data sets simultaneously is with a stack plot, which shows different data sets in a vertical stack. Although data can be stacked in both bar charts and line charts, the latter are much more common. Page 115 Copyright © 2009 Pearson Education, Inc. Slide 3.3- 9

Copyright © 2009 Pearson Education, Inc. EXAMPLE 3 Stacked Line Chart Figure 3.22 shows death rates (deaths per 100,000 people) for four diseases since 1900. Based on this graph, what was the death rate for cardiovascular disease in 1980? Discuss the general trends visible on this graph. Page 115 Figure 3.22 A stack plot using stacked wedges. Sources: National Center for Health Statistics, American Cancer Society. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 10

Copyright © 2009 Pearson Education, Inc. EXAMPLE 3 Stacked Line Chart Solution: Each disease has its own color-coded region, or wedge; note the importance of the legend. The thickness of a wedge at a particular time tells us its value at that time. For 1980, the cardiovascular wedge extends from about 180 to 620 on the vertical axis, so its thickness is about 440. This tells us that the death rate in 1980 for cardiovascular disease was about 440 deaths per 100,000 people. The graph shows several important trends. First, the downward slope of the top wedge shows that the overall death rate from these four diseases decreased substantially, from nearly 800 deaths per 100,000 in 1900 to about 525 in 2003. The drastic decline in the thickness of the tuberculosis wedge shows that this disease was once a major killer, but has been nearly wiped out since 1950. Meanwhile, the cancer wedge shows that the death rate from cancer rose steadily until the mid-1990s, but has dropped somewhat since then. Page 115 Copyright © 2009 Pearson Education, Inc. Slide 3.3- 11

Copyright © 2009 Pearson Education, Inc. Geographical Data The energy use data in Table 3.3 are an example of geographical data, because the raw data correspond to different geographical locations. Page 116 We used these data earlier to make a frequency table (Table 3.4), a histogram (Figure 3.8), and a stem-and-leaf plot (Figure 3.9). Figure 3.23 Geographical data can be displayed with a color-coded map. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 12

Copyright © 2009 Pearson Education, Inc. TIME OUT TO THINK What can you learn from the histogram in Figure 3.8 that you cannot learn easily from the geographical display in Figure 3.23? (Both are reproduced on the next slide.) What can you learn from the geographical display that you cannot learn from the histogram? Do you see any surprising geographical trends in Figure 3.23? Explain. Page 116 Copyright © 2009 Pearson Education, Inc. Slide 3.3- 13

Copyright © 2009 Pearson Education, Inc. Pages 105 and 116 Figure 3.23 Geographical data can be displayed with a color-coded map. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 14

Copyright © 2009 Pearson Education, Inc. Figure 3.24 shows a contour map of temperature over the United States at a particular time. Each of the contours (lines) connects locations with the same temperature. For example, the temperature is 50°F everywhere along the contour labeled 50° and 60°F everywhere along the contour labeled 60°. Between these two contours, the temperature is between 50°F and 60°F. Note that greater temperature differences mean more tightly spaced contours. For example, the closely packed contours in the northeast indicate that the temperature varies sub- stantially over small distances. Page 117 Figure 3.24 Geographical data that vary continuously, such as temperatures, can be displayed with a contour map. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 15

Copyright © 2009 Pearson Education, Inc. Three-Dimensional Graphics Each of the three axes in Figure 3.27 carries distinct information, making the graph a true three-dimensional graph. Researchers studying migration patterns of a bird species (the Bobolink) counted the number of birds flying over seven New York cities throughout the night. As shown on the inset map, the cities were aligned east-west so that the researchers would learn what parts of the state the birds flew over, and at what times of night, as they headed south for the winter. Notice that the three axes measure number of birds, time of night, and east-west location. Pages 118-119 Figure 3.27 This graph shows true three-dimensional data. Source: New York Times. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 16

Copyright © 2009 Pearson Education, Inc. Combination Graphics EXAMPLE 6 Olympic Women Describe three trends shown in Figure 3.28. Pages 119-120 Figure 3.28 Women in the Olympics. Source: Adapted from the New York Times. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 17

Copyright © 2009 Pearson Education, Inc. Solution The line chart shows that the total number of women competing in the summer Olympics has risen fairly steadily, especially since the 1960s, reaching nearly 5,000 in the 2004 games. Figure 3.28 Women in the Olympics. Source: Adapted from the New York Times. Pages 119-120 The pie charts show that the percentage of women among all competitors has also increased, reaching 44% in the 2004 games. The bold red numbers at the bottom show that the number of events in which women compete has also increased dramatically, reaching 135 in the 2004 games. Copyright © 2009 Pearson Education, Inc. Slide 3.3- 18

Copyright © 2009 Pearson Education, Inc. TIME OUT TO THINK Which of the trends shown in Figure 3.28 are likely to continue over the next few Olympic games? Which are not? Explain. Page 120 Copyright © 2009 Pearson Education, Inc. Slide 3.3- 19

Copyright © 2009 Pearson Education, Inc. The End Copyright © 2009 Pearson Education, Inc. Slide 3.3- 20