Introduction to the Practice of Statistics Section 1'1

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Introduction to the Practice of
StatisticsSection 1.1

• Alan Craig
• 770-274-5242
• acraig_at_gpc.edu

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Objectives 1.1

• Define statistics
• Understand the process of statistics
• Distinguish between qualitative and quantitative
  variables
• Distinguish between discrete and continuous
  variables

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Definition

• Statistics
• The science of collecting, organizing,
  summarizing, and analyzing information in order
  to draw conclusions.

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Process
Process
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1
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Collect information needed to answer research ques
tions
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Identify research objective
Organize summarize information
Draw conclusions from information
Population
Sample
Descriptive Statistics
Inferential Statistics
Individual
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Example 1
Experimental Design
Experimental Group
Control Group
Double Blind
Treatment
Placebo
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Variables
Types of Variables
Qualitative (Categorical) Variables
Quantitative Variables
Discrete (countable)
Continuous (measurable)
Nominal (categories)
Ordinal (rank order)
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Examples

• Qualitative
• Nominal
• Political affiliation, gender, ethnicity, marital
  status
• Ordinal
• Grades, socioeconomic status (SES), educational
  attainment, age group
• Quantitative
• Discrete (Interval)
• Age in years, number of siblings
• Continuous (Ratio)
• Height, weight, temperature, distance, age, time
  for a drug to be absorbed

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Questions

• What types of variables are these?
• Human blood types
• Household size
• High school class rank
• Religion
• Rotational speed of the planets
• Zip code
• Number of doctors in a county

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Data

• Data are the instances or observations of the
  variable
• Example
• Height is a variable
• The data are the measured heights of each student
  in this classroom.

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Questions

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