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Unit 1 Introduction to Statistics with history (1).pptx
- 1. Content Hours Unit 1: Basic Concepts of Statistics Introduction, Statistics defined, Functions, Scope, Limitations. 5 Unit 2: Diagrammatic and Graphical Representation Significance of Graphs and Diagrams, Difference between diagrams and graphs, Types of diagrams. 7 Unit 3: Measures of Central Tendency Introduction, Types of averages, Arithmetic Mean (Simple and Weighted), Harmonic Mean, Geometric Mean, Median, Mode. 15 Unit 4: Measures of Dispersion Range, Quartile Deviation, Mean Deviation ,Standard deviation, Coefficient of Variation. 13 Unit 5: Correlation and Regression Analysis Correlation and Regression Analysis - meaning, types, Probable Error, Karl Pearson’s & Rank correlation (only two direct variables), Meaning of Regression Analysis, Difference between Correlation and Regression Analysis, Regression Equations, Regression Co-efficient. 10 Unit 6: Time Series Introduction, Meaning and Definition, Uses, components of Time 10 1
- 2. Introduction Statistics 2 • Statistics is generally used to mean quantitative aspects of data management but as a subject of study. •it refers to body of principles and procedures developed for collection, classification, summarization and meaningful interpretation and for the use of such data. •The discipline is useful in converting random data to understandable information and aids in strategic business decision making. Statistics has its origin in Latin word Status, Italian word Statista and German term Statistik all of which mean “Political State”. In ancient times the beginning of Statistics was made to meet the requirements of State primarily and hence the name. Thus Statistic is treated as “Science of Statecraft”. Statistics is the science of Collection, Analysis, Presentation & Interpretation of numerical data. Introduction Origin Meaning
- 3. History of Statistics Statistics was known as the science of the state because it was used only by the Kings. So it got its development as ‘Kings’ subject or ‘Science of Kings’ or we may call it as “Political Arithmetic’s”. It was for the first time, perhaps in Egypt to conduct census of population in 3050 B.C. because the king needed money to erect pyramids. But in India, it is thought, that, it started dating back to Chandra Gupta Maurya’s kingdom under Chankya to collect the data of births and deaths. It has also been stated in Chankya’s Arthshastra. The term “Statistik- (in German) is coined by Gottfried Achenwall. In 1791 Sir John Sinclair introduced the term 'statistics' into English in his Statistical Accounts of Scotland. 3
- 4. Statistics day • Sir Ronald Aylmer Fisher is known as “ Father of Modern statistics. • 20th October is celebrated as World Statistics Day. It is Created by the United Nations Statistical Commission, and it was first time celebrated on 20 October 2010. The day is celebrated every five years. • Prof. Prasanta Chandra Mahalanobis is also known as the father of Indian Statistics. • In India, National Statistics Day is celebrated on June 29 on the birth anniversary of late Professor Prasanta Chandra Mahalanobis. Often referred to as the 'father of Indian statistics', Mahalanobis, was born on June 29, 1893, in Calcutta (now Kolkata), West Bengal. 4
- 5. The term Statistics is generally used in 2 senses- 1.Plural Sense 2. Singular Sense Definition Plural sense • Statistics is defined as “aggregate of facts affected to a marked extent by multiplicity of causes, numerically expressed, enumerated or estimated according to a reasonable standard of accuracy, collected in systematic manner, for a predetermined purpose and placed in relation to each other” - Prof.Horace Secrist 5
- 6. Meaning-Plural Statistics 6 Plural sense Features in Plural Sense Definitions for Plural sense Under this, the Statistics refers to numerical statement of facts related to any field of enquiry such as data related to income, expenditure, population etc in the sense of numerical data or Statistical data. Definitions- “Statistics are numerical statements of facts in any department of enquiry placed in relation to each other”-Bowley “By statistics we mean quantitative data affected to a marked extent by multiplicity of cause”- Yule and Kendall 1. Aggregation of facts- A single number does not constitute Statistics as no conclusion can be drawn from it. Only the aggregate of facts capable of offering meaningful information constitute Statistics. 2. Numerically expressed- Statistics are expressed in numbers. Qualitative data like rich, poor, beautiful, big etc cannot be termed Statistics. Contd….
- 7. Meaning-Plural Statistics 7 Features in Plural sense 3. Affected by Multiple causes- Statistics is not impacted by only 1 factor as multitude of factors influence it. For e.g rise in prices can be attributed to reduction in supply, increase in demand, rise in input costs etc. 4. Reasonable Accuracy- A reasonable degree of accuracy must be maintaining while collecting the statistical data. 5. Placed in relation to others- Such data is called Statistics which is mutually related and comparable. Height of 40 people cannot be compared with age of 40 people as data is not related. 6. Pre-determined purpose- Data collected without any purpose or randomly will only be a numerical value and not Statistics. 7. Enumerated or Estimated- Data can either be collected by estimation (if the field of investigation is very vast) or enumeration (for smaller set of data). 8. Collected in systematic manner- Haphazardly collected data will not provide conclusive evidence so systematic collection should be planned beforehand.
- 8. Meaning-Singular Statistics 8 Features in Singular sense Singular sense Definitions Under this, Statistics refers to science in which we deal with techniques and methods for collecting, classifying, presenting, analyzing and interpreting the data in the meaning of Statistical methods. Definitions- “Statistics may be defined as the collection, presentation, analysis and interpretation of numerical data.”-Croxton and Cowden “Statistics is the science which deals with the collection, classification and tabulation of numerical facts as a basis for the explanation, description and comparison of phenomena- Lovitt Given the definitions, the following stages of Statistics emerge- 1. Collection of data- Decide how, where, when, what kind of data to be collected. 2. Organization of data- Organize the collected data to make it comparable and simple. 3. Presentation of data- Make the data intelligible, brief and attractive. 4. Analysis of data- To draw conclusions, analysis of data is required by different methods e.g. central tendency, correlation. 5. Interpretation of data- Comparison and conclusions in simple and easy language.
- 9. Scope Statistics 9 The scope of Statistics may be classified into following 3 parts- Nature The study of nature is to find out whether Statistics is Science or Art As a science- It studies the Statistical data As a Art- It makes use of data to solve problems of real life. Subject Matter The subject matter of statistics is divided into 2 parts- 1. Descriptive statistics- It describes the data and consists of methods and techniques to explain characteristics of data. The methods can either be graphical or computational. 2. Inferential Statistics- It deals with methods which describe the characteristics of population or making decisions concerning population on the basis of sample results. Contd….
- 10. Functions Statistics 10 1. Expression of facts in numbers(presentation) 2. Simple presentation(simplification) 3. Enlarges individual knowledge and experience 4. It compares facts(comparison) 5. Facilitates policy formulation 6. It helps other science in testing their laws 7. It helps in forecasting
- 11. Limitations Statistics 11 1. Study of Numerical facts 2. Study of Aggregates only 3. Not the only method 4. Homogeneity of data 5. Results are true only on an average 6. Without reference results may prove wrong 7. Can be used by experts only 8. Misuse of Statistics is possible Limitati ons
- 12. Uses & Importance Statistics 12 1. Importance for administrators- Administrators use data for varied purposes and Statistics provide useful tools for decision making support. 2. Importance for business, industry and agriculture- Estimating demand and supply, studying seasonal changes, understanding trade cycles, consumer profiling, product life cycle analysis are examples of some of the functions that Statistics can perform for business, industry and agriculture. 3. Importance in Economics- Statistics is basis of Economics as it helps establishing the assumptions. Almost all the economic aggregates are measured with the help of Statistics. 4. Importance for Politicians and in Social field- For formulating social, economic, educational, industrial and other policies, politicians draw great support from Statistics discipline. Existing social problems can only be brought to fore front with the help of data analysis. The effectiveness of existing policies for social change can be measured by statistical tools. 5. Importance for banking and insurance industry- Bankers use statistics for estimating credit growth, risk analysis, portfolio management and insurers for establishing appropriate premiums looking at life expectancies.