Lecture Statistical techniques in business and economics - Chapter 1: What is statistics?

Chapter 1 - What is statistics? When you have completed this chapter, you will be able to: Explain what is meant by statistics, identify the role of statistics in the development of knowledge and everyday life, explain what is meant by descriptive statistics and inferential statistics, distinguish between a qualitative variable and a quantitative variable,...

What is Statistics?

When you have completed this chapter, you will be able to:

 Explain what is meant by 

statistics.

Identify the role of statistics in the development  

                of knowledge and everyday life.

 Explain what is meant by  descriptive  statistics 

and  inferential  statistics.

9  Gain an overview of the art and science of 

statistics. 

We recommend that you read this chapter at least twice, 

once at the beginning and once at the end of your course!

in everyday life

Who uses Who uses Statistics? Statistics?

Those using Statistical techniques include :

Marketers Marketers Accountants Accountants

Hospitals Hospitals

Investors Investors

Who uses Who uses Statistics? Statistics?

Sports

Types of  Statistics

  making inferences 

about  a population,            based on  

sample            information.

Descriptive Descriptive Inferential Inferential

Identify the following…

    C   Wine tasters sip a few drops         

of wine to make a decision                  with respect to 

all the wine        waiting to be 

A    A Gallup poll found that 83%      

 of the people in a survey knew 

which country won the gold  medal in Men’s Hockey in 2002. 

The Method of  Experimentation

The Method of  Experimentation

Rules of  Logic

Inductive Method Inductive Method Deductive Method

The Method of  Experimentation

The Method of  Experimentation

  average height of penguins in Antarctica.

Let’s review the steps they would take to 

prepare the estimate.

A population is a                 collection of      

      all possible  individuals, objects,       

        or     

measurements of interest

What we now need is…

From

…which are deemed to be representative of the …which are deemed to be representative of the

Take a  Measurement 

…to put the data

into a

readable and understandable

format!

Displaying Data Results Displaying Data Results

Two methods that can be

used to ‘see’

what the data conveys are

Tables and  Graphs/Charts

Line Scatter

Histogram

Pie

Bar

Why take a sample instead of studying  every member of the population?

Why take a sample instead of studying  every member of the population?

   Costs of surveying the entire population           may be too large or prohibitive

  Destruction of elements during  investigation

  Accuracy of results

More in chapter 8 …

methods will help you make  these 

decisions more effectively.

Quantitative

Qualitative

Numerical Observations

 Categorical  Observations

Types of Data

Variables

Country of Birth

U.K.

Germany Taiwan China India Japan Russia

Country of Birth

U.K.

Germany Taiwan China India Japan Russia

Eye Colour Blue Brown Hazel Green Red

Eye Colour Blue Brown Hazel Green Red

Gende

r Male Fema le

Gende

r Male Fema le

Qualitative – or Attribute Qualitative – or Attribute

Variables

Minutes to

end of Class

55 45 30 5 0

Number of Children

in

a Family

1 2 3

4

…

Number of Children

in

a Family

1 2 3

4

…

Number of Two- Door Garages

in a Street

10 20 30 40

Number of Two- Door Garages

in a Street

10 20 30 40

Number of

Satisfied Maple Leafs Fans

0 20 30 40

…

Number of

Satisfied Maple Leafs Fans

0 20 30 40

…

Quantitative – Numeric Quantitative – Numeric

Variables

Quantitative Numerical Observations

Numerical Observations

Summary of Types of Variables Summary of Types of Variables

Data Data

Qualitative

 Categorical  Observations

Quantitative Numerical

Observations Discrete Discrete Continuous Continuous (number of children) (time used for an exam)

Government of  Canada & Provinces www.gc.ca

www.theweathernetwork.com www.mcgrawhill.ca/college/lind

For Example…At home, over the telephone, by 

mail, by email, in the street, and at shopping malls!

Nominal Ordinal Interval   Ratio

Data can only be classified into categories or counted  and cannot be arranged  in any particular order  

Data can only be  classified into categories  or  counted 

Nominal Example Example M  &  M s

… involves  data arranged in some order , but         the  differences between data values       

…similar to the  Ordinal Level ,      

with the additional property              that meaningful amounts of differences between 

data values can be determined. 

There is no natural zero point

Example Example

Temperature on the Celsius scale.

“There are three kinds of lies…

Benjamin Disraeli  said…

“There are three kinds of lies…

Review the following three slides and 

notice the effect        that the       

different scales       

  have on your interpretation of the 

pattern between      

0  1  2  3  4  5  6  7  8  9  10 11  12

3200 3000 2800 2600 2400 2200 2000

7       8         9        10        11       12

3000 2500 2000 1500 1000   500       0

1000 1500 2000 2500 3000

Chart 1­11C

3200 3000 2800 2600 2400 2200 2000

Test your learning Test your learning … …

Online Learning Centre for quizzes

extra content data sets

searchable glossary access to Statistics Canada’s  E­Stat data

…and much more!

This completes Chapter 1.