7-10 Misleading Graphs Problem of the Day Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes

7-10 Misleading Graphs Warm Up Use the graph for Questions What network had the most viewers? 2. What network had the fewest viewers? 3. What network(s) had about the same viewer ship? ABC FOX CBS, NBC

7-10 Misleading Graphs Problem of the Day A bar graph has vertical axis intervals of 6. How would the graph look if the intervals were twice as large? It would be half as tall.

7-10 Misleading Graphs Learn to identify and analyze misleading graphs.

7-10 Misleading Graphs A data display that distorts information in order to persuade can be misleading. An axis in a graph can be “broken” to make the graph easier to read. However, a broken axis can also be misleading. In the graph at right, the cost per minute for service with Company B looks like it is twice as much as the cost for service with Company A. In fact, the difference is only $0.10 per minute.

7-10 Misleading Graphs Both line graphs show the high temperature Monday through Friday. Which graph could be misleading? Why? Additional Example 1 The graph at right could be misleading. It gives the impression of greater temperature change because the vertical axis does not begin at zero.

7-10 Misleading Graphs Check It Out: Example 1 Graph B could be misleading. The vertical axis does not begin at zero, so differences in scales appear greater. Graph B Which graph could be misleading? Why? Price per meal Gino’s Village Grill Pasta City City Diner Graph A Gino’s Village Grill Pasta City City Diner Price per meal Average Restaurant Meal Price

7-10 Misleading Graphs Explain how you could redraw the graph so it would not be misleading. Additional Example 2A: Analyzing Misleading Graphs Draw the entire vertical scale on the graph.

7-10 Misleading Graphs Additional Example 2B: Analyzing Misleading Graphs Explain how you could redraw the graph so it would not be misleading. Draw the vertical scale with equal spacing between marks so that the distance between 0 and 18,000 equals the distance between 18,000 and 36,000.

7-10 Misleading Graphs Explain how you could redraw the graph so it would not be misleading. Check It Out: Example 2A Mon Tue WedThu Fri Taxicab Fares Fare ($) ‏ Draw the entire vertical scale on the graph. The vertical axis is broken, so differences in fare appear greater.

7-10 Misleading Graphs Explain how you could redraw the graph so it would not be misleading. Check It Out: Example 2B Water Consumed Mark FrankMilaYvonne Ounces of Water Draw the entire vertical scale on the graph. The vertical axis does not start at zero so differences in water consumed seem greater.

7-10 Misleading Graphs Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems

7-10 Misleading Graphs Lesson Quiz Explain why each graph could be misleading and why. The vertical scale on the graph is not small enough to show the changes. The scale does not start at 0, so it looks like fewer people like each type of animal

7-10 Misleading Graphs 1. Explain why the graph could be misleading. A. The vertical axis is broken, so it looks like fewer people like each type of drink. B. The vertical scale is not small enough to see differences. C. The intervals are not equal to compare the frequencies. D. The vertical axis does not begin with zero. Lesson Quiz for Student Response Systems

7-10 Misleading Graphs 2. Explain why the graph could be misleading. A. The vertical axis is broken, so difference in the number of birds appears smaller. B. The scale of the graph is not divided into equal intervals, so differences in the number of birds appear less than the actual. C. The vertical scale is not small enough to show the actual differences. Lesson Quiz for Student Response Systems