Transcript Lesson 1.1

An Overview of
Statistics
Lesson 1.1
What is statistics?
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Statistics is the science of
collecting, organizing, analyzing,
and interpreting data in order to
make decisions.
You are exposed to statistics
almost every day!
Data
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Data consist of information from
observations, counts,
measurements, or responses.
The singular for data is datum.
Data Sets
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A population is the collection of
all outcomes, responses,
measurements, or counts that
are of interest.
A sample is a subset of a
population.
Examples
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A randomly selected group of
100 seniors at GCHS are
surveyed about their future
goals regarding further
education. Identify the
population and sample.
Parameter vs. Statistic
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A parameter is a numerical
description of a population
characteristic.
A statistic is a numerical
description of a sample
characteristic.
Population Parameter or
Sample Statistic?
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In a recent study, 400 actuaries
were surveyed. The average
salary for a starting actuary was
$45,000.
Sample statistic
Population Parameter or
Sample Statistic?
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5.5% of the 2008 GCHS
graduates have taken probability
and statistics.
Population parameter
Study of Statistics
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There are two branches of statistics
we will be learning about this year:
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Descriptive statistics is the branch of
statistics that involves the organization,
summarization and display of data.
Inferential statistics is the branch of
statistics that involves using a sample to
draw conclusions about a population. A
basic tool in the study of inferential
statistics is probability.
Descriptive of Inferential?
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A survey conducted among 1017
men and women by Opinion
Research Corporation International
found that 76% of women and 60%
of men had had a physical
examination within the previous year.
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Identify the descriptive aspect of this
survey.
What inferences could be drawn from
this survey?
Descriptive of Inferential?
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Descriptive statistics invole the
statement “76% of women and 60%
of men had a physical
examination…”
An inference drawn from the study is
that a higher percentage of women
had a physical examination within
the previous year (talking about the
entire population!)
Exercises
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Pages 6-8 #1-4 all, 5-31 odd,
34-35 all.