Chapter 1

Question 1

What are Statistics?

Answer 1

Two major branches of Statistics:

• Desciptive statistics
• Inferential statistics.

Question 2

What are Descriptive statistics?

Answer 2

Descriptive statistics deals with methods of organising, summarising, and presenting data in a convenient and
informative way.

• Using graphical techniques to help statistics practitioners to present data in ways that make it easy for the reader to extract useful information.
• Using numerical measures to summarise data.

Question 3

What are Inferential statistics?

Answer 3

Inferential statistics is also a set of methods, but it is used to draw conclusions or inferences about characteristics of populations based on sample statistics calculated from sample data.

Question 4

What are Population and sample?

Answer 4

Key Statistical concepts:
1/ Population
A population is the group of all items (data) of interest.
Population is frequently very large; sometimes infinite.
E.g. 1. All current million or so members of an automobile club.

2/ Sample
A sample is a set of items (data) drawn from the population of interest.
Sample could potentially be very large, but much less than the population.
E.g. 1. A sample of 500 members of the automobile club selected.

Question 5

What are Parameter and Statistics?

Answer 5

Question 6

What is Statistical inference?

Answer 6

We use sample statistics to make inferences about population parameters.

Therefore, we can produce an estimate, prediction, or decision about a population based on sample data.

Question 7

What are Confidence and Significance levels?

Answer 7

Using Confidence level and Significance level to measure the “reliability” of satatistical inference.

Question 8

Provide examples of practical applications in which
statistics have a major role to play.

Answer 8

Page 26 - Lecture A_PPT.pdf