1. 7-10 Misleading Graphs Warm Up Problem of the Day Lesson Presentation
Course 2

2. Misleading Graphs 7-10 Warm Up Use the graph for Questions 1-3.
Course 2
7-10
Misleading Graphs
Warm Up
Use the graph for Questions 1-3.
1. 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
ABC, CBS, NBC

3. Misleading Graphs 7-10 Problem of the Day
Course 2
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.

4. Course 2
7-10
Misleading Graphs
Learn to identify and analyze misleading graphs.

5. Course 2
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.

6. Misleading Graphs 7-10 Additional Example 1
Course 2
7-10
Misleading Graphs
Additional Example 1
Both line graphs show the high temperature Monday through Friday. Which graph could be misleading? Why?
The graph on the right could be misleading. It gives the impression of greater temperature change because the vertical axis does not begin at zero.

7. Average Restaurant Meal Price
Course 2
7-10
Misleading Graphs
Check It Out: Example 1
Graph B
Which graph could be misleading? Why?
Price per meal 25 20 15 10
Gino’s
Village Grill
Pasta City
City Diner
Graph A 30
Average Restaurant Meal Price
Graph B could be misleading. The vertical axis does not begin with zero, so differences in scales appear greater.

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

9. Additional Example 2B: Analyzing Misleading Graphs
Course 2
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.

10. Misleading Graphs 7-10 Check It Out: Example 2A
Course 2
7-10
Misleading Graphs
Check It Out: Example 2A
Explain how you could redraw the graph so it would not be misleading.
Mon Tue Wed Thu Fri 13 12 11 10
Taxicab Fares
Fare ($)
Draw the entire vertical scale on the graph. The vertical axis is broken, so differences in fare appear greater.

11. Misleading Graphs 7-10 Check It Out: Example 2B
Course 2
7-10
Misleading Graphs
Check It Out: Example 2B
Explain how you could redraw the graph so it would not be misleading.
Water Consumed 48 40 32 24 16
Mark
Frank
Mila
Yvonne
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.

12. Misleading Graphs 7-10 Lesson Quiz
Course 2
7-10
Misleading Graphs
Lesson Quiz
Explain why each graph could be misleading and why. 1. 2.
The scale does not start at 0, so it looks like fewer people like each type of animal.
The vertical scale on the graph is not small enough to show the changes.