Principles of Statistics

By Obaid Mahmoud Mohsen Al-Zubaie

The book contains seven chapters. The first chapter is devoted to including what is statistics, why we study statistics, and several concepts and definitions. The second chapter included of some of the steps of the statistical method, with an explanation of the mechanism for preparing the questionnaire. The third and fourth chapters were devoted to reviewing measures of central tendency and measures of dispersion and variation. While the fifth chapter included a review of index numbers, and the sixth chapter sheds light on quality control. While the seventh chapter included the probabilities and probability distributions. Each chapter includes several applied examples and case studies, in addition to each chapter containing a set of exercises and case studies with their solutions.

• Language: العربية
• Publisher: tevoi
• Release date: Feb 18, 2024

Book preview

Preface

Statistics is considered one of the sciences that grew and developed in the last century to become a science of bases and rules and to occupy an important position among other sciences.

It is the instrument of the trail world in any scientific research field, whether the subject was social, economic, or educationalist. in any activity whether it was humanistic or humanistic.

It became the producer instrument to control its production we don't exceed the truth if we say that it is today the state modern instrument in evaluating and planning its sectors.

This book is intended for students whom they don't have a strong background in mathematics.

The explanation of statistical methods and concepts is clear and concise, it is easy to understand, and it contains many examples and case studies provide additional illustration of applications of statistics in administration and accounting, in addition to that every chapter contains a set of exercises.

I must show my gratitude to all those who help to put this work in its present form.

Any suggestion from readers for future revisions would be greatly appreciated. Such suggestion can be sent to the email: [e-mail]

Prof.Dr. obaed M.M.Alzawbai

October 2023

Chapter One

Some Basic Principles

1.1 What Is statistics.

The word statistics means the counting and limitation, it was even called the science of counting.

The word statistics was used to refer to works and counting of the state in the affairs of war, taxes, population, the birth rate and the death rate ……. etc.

In the more common usage statistics refers to numerical facts the numbers that represent the income  of family the age of a student the starting salary of atypical college graduate

Nowadays statistics increasingly developed, and it became independent science.

1.2 The Importance Of statistics :( Why study statistics)

Life is full of problems and phenomena that require study and research to draw conclusions and make decisions decision about their treatment with a correct scientific style and the operation of study of the problems on the phenomenon, we can search it in the way of what is called the scientific me thud which consists of sequent stages according to which we get the required result. Or we can search the problem in the way of what is called the scientific method that provides the investigator with objective style of searching.

Then it is applied by expressing the problem or the phenomenon which we intend to study numerically. We mean to say that the opportunity for applying this method is alleged to the ability of expression that phenomenon numerically. The advantage of this method make it widely applied for its easy use it helps in reducing the phenomenon it contributes to reducing the efforts done for fulfillment in addition to this it contributes to reducing the time the fulfillment lasts.

The scientific method has stages we are going to explain them in detail later.

The importance of statistics occurs through its connection with many fields’ daily life activities.

It is connected strongly either on the individual or groups level some fields in which statistics is applied will be mentioned later.

1. the social sciences which include

a. the population counting meaning to know the people characteristics in relation to the age, the economic activity and the educational level.

b. the study of the movement of population in terms of increase decrease and migration

c. the study of the dominant direction and opinions in the society 

2. the economic science which include:

a. the study of the foreign commerce

b. the study of prices changes.

c. statistics of agricultural and industrial production and their needs

e. the national income statistics and its sources

3. in the field natural  and organic sciences which include

a. the weather changes study

b. the study of the organic qualities of the animal and plants and study the effectiveness of medicine and chemical compositions.

4.in field of education and psychology

a. the study of the actual abilities of pupils in the various education stages and comparing the intelligence in terms of certain factors.

b. the study of effectiveness of orders and the various education methods

5.in field of the geometrical and industrial sciences

a. the statistical control for the production qualities

b. examines the products at their find from before the customer.

c. limits the storage level.

6. in the planning field 

The importance of statistics appears largely in the societies of the central planning system in the societies where decision making moves from the hand of million individuals to the hands of the planning staffs that is way, they are used in considered a necessity to everyone takes parting the planning operation.

7. the statistics and administration

We can look at the administration operation as function or duties of the manager we can also limit the constituents of the administration operation as follow which at the same time stands for the manager’s duties:

a. recognizing the problem: -

one of the activities that the manager has to do is to recognize the problem and related reasons. He has to put the major and the minor goals then collects the information about the beneficiaries from the interest he also puts the programmers and the analytical studies after that he begins to carry out what he has planned before.

b. planning

Planning means the operation of making principled decisions about what is expected to happen in the future that means that no planning is without enough statistical