1 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman M ARIO F. T RIOLA E IGHTH E DITION E LEMENTARY S TATISTICS Section 1-3 Uses and Abuses of Statistics

2 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Uses of Statistics  Almost all fields of study benefit from the application of statistical methods

3 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Abuses of Statistics  Bad Samples

4 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Definitions  self-selected survey (or voluntary response sample) one in which the respondents themselves decide whether to be included

5 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Abuses of Statistics  Loaded Questions  Misleading Graphs  Bad Samples  Small Samples

6 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Bachelor High School Degree Diploma Figure 1-1 Salaries of People with Bachelor’s Degrees and with High School Diplomas $40,000 30,000 25,000 20,000 $40,500 $24,400 35,000 $40,000 20,000 10,000 0 $40,500 $24,400 30,000 Bachelor High School Degree Diploma (a)(b)

7 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman We should analyze the numerical information given in the graph instead of being mislead by its general shape.

8 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Abuses of Statistics  Pictographs  Bad Samples  Small Samples  Loaded Questions  Misleading Graphs

9 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Figure 1-2 Double the length, width, and height of a cube, and the volume increases by a factor of eight

10 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman Abuses of Statistics  Precise Numbers  Distorted Percentages  Partial Pictures  Bad Samples  Small Samples  Loaded Questions  Misleading Graphs  Pictographs

11 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman “Ninety percent of all our cars sold in this country in the last 10 years are still on the road.”

12 Chapter 1. Section 1-3. Triola, Elementary Statistics, Eighth Edition. Copyright Addison Wesley Longman  Bad Samples  Small Samples  Loaded Questions  Misleading Graphs  Pictographs  Precise Numbers  Distorted Percentages  Partial Pictures Abuses of Statistics  Deliberate Distortions