1. Misleading Graphs and Statistics
9-6
Misleading Graphs and Statistics
Warm Up
Problem of the Day
Lesson Presentation
Course 3

2. Misleading Graphs and Statistics
Course 3
9-6
Misleading Graphs and Statistics
Warm Up
1. How many students
say oranges are their favorite?
2. What is the least popular fruit?
3. How many students answered
the survey?
Use the graph for problems 1-3 40
Kiwi 90

3. Misleading Graphs and Statistics
Course 3
9-6
Misleading Graphs and Statistics
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

4. Misleading Graphs and Statistics
Course 3
9-6
Misleading Graphs and Statistics
Learn to recognize misleading graphs and statistics.

5. Misleading Graphs and Statistics
Course 3
9-6
Misleading Graphs and Statistics
Graphs and statistics are often used to persuade. Advertisers and others may accidentally or intentionally present information in a misleading way.

6. Additional Example 1A: Identifying Misleading Graphs
Course 3
9-6
Misleading Graphs and Statistics
Additional Example 1A: Identifying Misleading Graphs
Explain why each graph is misleading.
The graph suggests that the stock will continue to increase through 2020, but there’s no way to foresee the future.

7. Additional Example 1B: Identifying Misleading Graphs
Course 3
9-6
Misleading Graphs and Statistics
Additional Example 1B: Identifying Misleading Graphs
Explain why each graph is misleading.
Because the scale leaves out 0 to 100, the bar heights make it appear that the sixth grade sold about three times as many tickets as either of the other two grades. In fact, the sixth grade sold only about 20% more.

8. Additional Example 1C: Identifying Misleading Graphs
Course 3
9-6
Misleading Graphs and Statistics
Additional Example 1C: Identifying Misleading Graphs
Explain why each graph is misleading.
The scale is so compressed that it’s hard to see any difference among the brands.

9. Misleading Graphs and Statistics Insert Lesson Title Here
Course 3
9-6
Misleading Graphs and Statistics
Insert Lesson Title Here
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

10. Misleading Graphs and Statistics Insert Lesson Title Here
Course 3
9-6
Misleading Graphs and Statistics
Insert Lesson Title Here
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

11. Insert Lesson Title Here
Course 3
9-6
Misleading Graphs and Statistics
Insert Lesson Title Here
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

12. Additional Example 2: Identifying Misleading Statistics
Course 3
9-6
Misleading Graphs and Statistics
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.

13. Additional Example 2: Identifying Misleading Statistics
Course 3
9-6
Misleading Graphs and Statistics
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 2.
Although Jacob scored only 2 goals, he may have played most of his time on defense.

14. Misleading Graphs and Statistics
Course 3
9-6
Misleading Graphs and Statistics
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.

15. Misleading Graphs and Statistics
Course 3
9-6
Misleading Graphs and Statistics
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.

16. Misleading Graphs and Statistics Insert Lesson Title Here
Course 3
9-6
Misleading Graphs and Statistics
Insert Lesson Title Here
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.

17. Misleading Graphs and Statistics Insert Lesson Title Here
Course 3
9-6
Misleading Graphs and Statistics
Insert Lesson Title Here
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.”
A low outlier was included in order to bring down the average cost.