Transcript Lesson 1.1
An Overview of
Statistics
Lesson 1.1
What is statistics?
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
Data consist of information from
observations, counts,
measurements, or responses.
The singular for data is datum.
Data Sets
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
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
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?
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?
5.5% of the 2008 GCHS
graduates have taken probability
and statistics.
Population parameter
Study of Statistics
There are two branches of statistics
we will be learning about this year:
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?
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.
Identify the descriptive aspect of this
survey.
What inferences could be drawn from
this survey?
Descriptive of Inferential?
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
Pages 6-8 #1-4 all, 5-31 odd,
34-35 all.