Warm Up Problem of the Day Lesson Presentation Lesson Quizzes

Use the graph for problems 1-3. Warm Up 1. How many students like oranges? Use the graph for problems 1-3. 40 2. What is the least-liked fruit? Kiwi 3. How many students answered the survey? 90

Problem of the Day Create a data set with five values that will have a mean of 20, a median of 18, and a mode of 15. Possible answer: 15, 15, 18, 19, 33

Learn to recognize misleading graphs and statistics.

Graphs and statistics are often used to make advertisements visually appealing. Some advertisements, however, use art to mislead consumers.

Additional Example 1A: Identifying Misleading Graphs Explain why each graph is misleading. The intervals used on the vertical axis are not equal.

Additional Example 1B: Identifying Misleading Graphs Explain why each graph is misleading. The icons represent different quantities of food and are different sizes.

% of Return on Investment Check It Out: Example 1A Explain why each graph is misleading. % of Return on Investment 60 50 The graph suggests that the rate of investment return will continue to increase, but there are no guarantees 40 30 20 10 1 2 3 4 5* 6* * projected

Preferred Juice Flavors Check It Out: Example 1B Explain why each graph is misleading. Preferred Juice Flavors The graph appears to indicate that significantly more people prefer grape drink over the others when in fact there is a small margin of difference. (0 to 140 is not graphed) 150 148 146 144 142 140 Grape Cherry Apple

Explain why each graph is misleading. Check It Out: Example 1C Explain why each graph is misleading. Drink Sales This graph is too compressed to see much difference between the brands indicating that they are fairly equal. 120 No data from 50 to 120 100 80 60 40 20 Brand X Brand Y Brand Z

Additional Example 2: Identifying Misleading Statistics Explain why each statistic is misleading. A. Four out of five dentists surveyed preferred UltraClean toothpaste. This statement does not give the sample size or state what UltraClean toothpaste was compared with. B. Shopping at Save-a-Lot can save you up to $100 a month! The words save up to $100 mean that the maximum you can save is $100, but there is no guarantee that you will save that amount.

Additional Example 2: Identifying Misleading Statistics Explain why each statistic is misleading. C. Sam scored 43 goals for his soccer team during the season, and Jacob scored only 10. A reporter claims that Sam is a better player than Jacob. Although Jacob scored only 10 goals, he may have played most of his time on defense.

Check It Out: Example 2 Explain why each statistic is misleading. A. Four out of five breeders recommend Pet Blend dog food for a healthier coat. This statement does not give the sample size or state what Pet Blend dog food was compared with. B. Fruity Squares makes the cereal 100% more fun. You cannot measure how much fun Fruity Squares makes the cereal.

Check It Out: Example 2 Explain why each statistic is misleading. C. The total revenue for bathing suits sold in May at Worthman’s Florida stores is 250,000. The total revenue for bathing suits sold in May at Worthman’s North Dakota stores is 10,000. The states have different populations and climates.

Lesson Quiz for Student Response Systems Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems 15

Lesson Quiz: Part I Explain why each graph or statistic is misleading 1. Possible answer: The difference in size between the car and truck symbols distorts the comparison.

Lesson Quiz: Part II Explain why each graph or statistic is misleading 2. A budget area of a used-car lot has five cars on it, with prices of $4200, $4700, $4900, $5200, and $900 (a wrecked one). The car ad in the local paper reads “Average priced car on budget lot is $3980.” Only one car is less than the average price.

Lesson Quiz for Student Response Systems 1. Explain why the graph is misleading. A. There are more number of apples than oranges. B. There are more number of oranges than apples. C. The difference in the size between the apple and orange symbols distorts the comparison. D. The difference in the size between the apple and orange symbols makes it easier for comparison. 18

Lesson Quiz for Student Response Systems 2. Explain why the statistic is misleading. Tim scored 6, 1, 1, 2, 1, 1 goals during a football season. He told his friends that he scored an average of 2 goals per match. A. The differences in the scores are too small. B. His actual average is 3 goals per match. C. Sample size is too small. D. He scored more than 2 goals in only one match 19