Elementary Statistics
Introduction
🎯 LEARNING OBJECTIVES
By the end of this chapter, you should understand what statistics is and how it is used to
work with data. You will learn the statistical investigative process, distinguish between
descriptive and inferential statistics, recognize statistical questions, and apply these
concepts to real-world situations.
WHAT IS STATISTICS?
Statistics is the science of collecting, organizing, analyzing, and interpreting data to help us
make decisions and draw conclusions.
The simplest way to picture it:
DATA → FIND THE PATTERN → ANALYZE IT
THE INVESTIGATIVE PROCESS
In statistics, the investigative process starts with a question and ends with action.
• Ask questions to determine the problem or issue. A good question anticipates variability,
pertains to a group, and is clear and specific.
A weak question: Are college students stressed?
A stronger question: How many hours of sleep do college students get on an average night?
• Collect relevant data.
• Find patterns, relationships, differences, and observations in the data.
• Describe data through statistics and graphs.
• Interpret the data and draw conclusions.
A conclusion should always connect back to the evidence.
ASK → COLLECT → ANALYZE → CONCLUDE
DESCRIPTIVE VS INFERENTIAL STATISTICS
Descriptive statistics summarize the data you've collected. Examples: mean, median, mode,
graphs, tables, percentages, etc.
pg. 1
, EX 1.1
You survey 50 students and discover that their average study time is 12 hours per week. Is
this descriptive or inferential statistics?
Inferential statistics use sample data to make a conclusion, estimate, or prediction about a
larger population. To infer means to go beyond the data. Let’s do an example.
EX 1.2
You survey 50 students and use their results to estimate the average study time for all
students at the school. Is this descriptive or inferential statistics?
📌 SUMMARY
Descriptive statistics provides a summary of the data collected. Inferential statistics
uses that data to make predictions or generalizations about a larger group. The
investigative process progresses through asking questions, collecting data, analyzing it,
and drawing conclusions.
pg. 2
Introduction
🎯 LEARNING OBJECTIVES
By the end of this chapter, you should understand what statistics is and how it is used to
work with data. You will learn the statistical investigative process, distinguish between
descriptive and inferential statistics, recognize statistical questions, and apply these
concepts to real-world situations.
WHAT IS STATISTICS?
Statistics is the science of collecting, organizing, analyzing, and interpreting data to help us
make decisions and draw conclusions.
The simplest way to picture it:
DATA → FIND THE PATTERN → ANALYZE IT
THE INVESTIGATIVE PROCESS
In statistics, the investigative process starts with a question and ends with action.
• Ask questions to determine the problem or issue. A good question anticipates variability,
pertains to a group, and is clear and specific.
A weak question: Are college students stressed?
A stronger question: How many hours of sleep do college students get on an average night?
• Collect relevant data.
• Find patterns, relationships, differences, and observations in the data.
• Describe data through statistics and graphs.
• Interpret the data and draw conclusions.
A conclusion should always connect back to the evidence.
ASK → COLLECT → ANALYZE → CONCLUDE
DESCRIPTIVE VS INFERENTIAL STATISTICS
Descriptive statistics summarize the data you've collected. Examples: mean, median, mode,
graphs, tables, percentages, etc.
pg. 1
, EX 1.1
You survey 50 students and discover that their average study time is 12 hours per week. Is
this descriptive or inferential statistics?
Inferential statistics use sample data to make a conclusion, estimate, or prediction about a
larger population. To infer means to go beyond the data. Let’s do an example.
EX 1.2
You survey 50 students and use their results to estimate the average study time for all
students at the school. Is this descriptive or inferential statistics?
📌 SUMMARY
Descriptive statistics provides a summary of the data collected. Inferential statistics
uses that data to make predictions or generalizations about a larger group. The
investigative process progresses through asking questions, collecting data, analyzing it,
and drawing conclusions.
pg. 2
