1305AFE – Business Data Analysis
Trimester 3 - Logan and Online
Topic One
Introduction to Statistics
&
Data Collection
References:
ABS textbook (Selvanathan et al), Chapters 1
and 2

Part A: Intro to Statistics
2

3
Part A: Introduction to
Statistics
- Objectives
•
Define statistics
•
Define statistical terminologies
•
Population and Sample
•
Population Parameter and Sample statistics
•
Types of data:
numerical, nominal, ordinal, etc
•
Two major areas of Statistics
•
Descriptive Statistics
•
Statistical Inference

What is statistics?
Statistics is a body of principles and methods
used to extract useful information
from a
data set to assist people to make decisions
about questions of interest.
Data are actual observations that result from
an investigation or an experiment or a
survey.

5
What is Statistics?
•
“Statistics is a way to get information
from data”
Data
Statistics
Information
Data:
Facts collected
together for reference
or information.
Definitions: Oxford English Dictionary
Information:
Knowledge
communicated
concerning some
particular fact.
Statistics is a
tool
for creating
new
understanding
from a set of numbers.

Who Uses it?
•
Statistical techniques are used extensively
by marketing, accounting, quality
control, consumers, professional sports
people, hospital administrators,
educators, economists, politicians,
physicians, etc...

7
Statistical Terminology
•
Population
vs
Sample
•
Population Parameter
vs
Sample Statistic
N
n
µ
(Mu)
(X bar)
2
s
2
(sigma)
s
p
(p hat)
X
p
ˆ

8
Key Statistical Concepts
Population
•
a
population
is the group of all
items of interest to a
statistics practitioner.
•
frequently very large; sometimes infinite.
E.g. All Griffith university students
Sample
•
A
sample
is a set of data drawn from the population.
•
Potentially very large, but less than the population.
E.g. A random sample of 500 Griffith university students.

9
•
Populations have Parameters,
•
Samples have Statistics.
Parameter
Population
Sample
Statistic
Subset
Key Statistical Concepts…

10
Population
Parameters
µ
p
Sample
s
Sample statistics
are used to describe
what form the
population takes
Sample statistics can
also be used to draw
inferences about the parameters
of the population
A sample is selected
from the larger
population
x
_
p

11
Parameter
•
A descriptive measure of a
population.
•
e.g.: Average annual income of all Australians.
•
Proportion of defective shoes manufactured in a shoe factory.
Statistic
•
A descriptive measure of a
sample.
•
e.g.: Average annual income of 100 randomly selected Australians.
•
Proportion of defective shoes in 200 randomly selected shoes
manufactured in a shoe factory.
Key Statistical Concepts…

12
Selecting a Sample
•
A survey of the whole population is called
a CENSUS.

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- Fall '19