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# Overview of statistics

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### Overview of statistics

1. 1. Pre - Induction Programme By Prof. Manisha Phate
3. 3. In our day to day life statistics conveys a varietyof meanings to people. We find statistics innewspapers, journals, books, various reports,speeches, classroom lectures etc.Example:There are 940 females per 1000 males in india. For population UP in India stands at rank first.Maharashtra stands at second positionhaving 9.29% of total population.
4. 4. INTRODUCTION Density of population in Maharashtra is 365 per km square. And the sex ratio is 925 females per 1000 males. The literacy rate in Maharashtra is 82.91%. Most literate state in india is Kerala with 93.9%. Percentage of students whose name is starting with letter A, B, D, Y, The students who scored in between 50 to 70.
5. 5. ORIGIN AND GROWTH ORIGIN It is not a new discipline but as old as human society itself. It has been in use since the existence of life on earth. The word statistics comes from the Italian word statista (meaning statesman) or the German word statistik which means a political state. It was first used by Prof.Gottfried Achenwall (1719- 1772) Achenwall first defined the statistics as the political science of several countries. The word statistics appeared first time in a famous book – Elements of Universal Erudiction Science of statistics is originated from two main sources1. Government Records2. Mathemetics
6. 6. Govt. Records During good old days it is regarded as the science of statecraft. Because it was byproduct of the administrative activity of the state. This is earliest foundation because all cultures with a recorded history had recorded statistics and the recording as far as is known was done by govt. agents for governmental purpose. It has been in traditional function of govt. to keep records of population, births, deaths, taxes, crop yields etc. As the data was collected for governmental purposes statistics was then described as the science of kings or the science of statecraft.
7. 7. Statistics is said to be a branch of appliedmathematics.The present body of statistical methodsparticularly those concerned with drawinginferences about population from sample is basedon the mathematic theories.Numbers play an important role in statistics andhere the study of statistics involves methods ofrefining numerical and non numerical informationin to useful forms.
8. 8. There has been a phenomenal developmentin the use of statistics in several fields.Now a days it is a most important tool fortaking decisions in case of uncertainty.Two main factors which are responsiblethe development of statistics1. Increased demand for statistics2. Decreasing cost of statistics
9. 9. In present, considerable development has taken place inthe field of business, commerce, governmental activitiesand science. Statistics helps in formulating suitablepolicies and as such its need is increasingly being felt inall the spheres. Such as……….a) Government: As there is enlargement in Govt. functionsb) Sciences: Tremendous advancement in the existing sciences & also development of new branches.c) Research: Extensive research work is now being undertaken by many people.d) Time & Cost: Less time & cost to collect and process the data with the help of electronic machines such as calculators, computers etc.
10. 10. Decreasing Cost of StatisticsFollowing factors helps to decrease the cost Development of statistical theories: eg. Sampling Techniques Use of electronic machines: eg. Computer calculator Tools for Analysis: eg. SPSS
11. 11. STATISTICS - DEFINITIONThere have been many definitions of the term statistics:1. Webster: The classified facts representing the conditions of the people in a state. Especially those facts which can be stated in numbers or in tables of numbers or in any tabular classified arrangement.2. Yule & Kendall: By statistics we mean quantitative data affected to a marked extent by multiplicity of causes.
12. 12. STATISTICS - DEFINITION3 . Horace secrist: Statistics means aggregates of facts affected to a marked extent by multiplicity of causes ,numerically expressed, estimated according to reasonable standards of accuracy, collected in a systematic manner for a predetermined purpose and placed in relation to each other.;
13. 13. Above definition states certain charactristics whichnumerical data must possess in order that they maybe called statistics.Aggregates of facts:Affected to a marked extent by multiplicity ofcausesNumerically expressedEnumerated or estimated according to resonablestandards of accuracyCollected in a systematic mannerCollected for pre-detemined purposeShould be placed in Relation to each other.
14. 14. STATISTICS - DEFINITIONCroxton and cowden : Statistics may be defined as the collection, presentation analysis and interpretation of numerical data.Very simple and precise definition and talks about four stages of Statistics. Collection Presentation Analysis Interpretation
15. 15. Frequently used statistical terms Data Statistical Sample Variable Terms Population
16. 16. Data Data: This is simply a group of results of any scientific measurement.Eg. Collection of numbers representing height of students in a class, Marks in a class.
17. 17. Variable This is a characteristic that can assume different values and is usually represented by x. Eg. Age of students, sales figure of a commodity. Etc.
18. 18. Population A population or universe is the totality of items or things under consideration. It is the collection of all values of the variable under study. OR The complete collection of all elements (scores, people, measurements, and so on) to be studied. The collection is complete in the sense that it includes all subjects to be studied.
19. 19. Sample It is the portion of population or universe under consideration. And sampling is the process of selecting sample. OR A sub-collection of elements drawn from a population
20. 20. STATISTICS: SCIENCE & ART Its a subject of Debate.Science: systematized body of knowledge. It studies cause and effect relationship and attempts to make generalizations in the form of scientific principles or laws. It describes objectivity and avoids vague judgments. Science is Knowledge.Art: refers to the skill of handling facts so as to achieve a given objective. Having concern with ways & means of presenting and handling data making inferences logically and drawing relevant conclusions. Art is Action.Statistics: not a body of knowledge but a body of methods for obtaining knowledge.
21. 21. Functions of Statistics Presents facts in a definite form Simplifies mass of figures Facilitates comparison Helps in formulating & testing hypothesis Helps in prediction Helps in formulation of suitable policies.
22. 22. Definiteness To present general statements in a precise and definite form. As numerical statements are more convincing. Example: The production of wheat in India in 2006-07 was higher than that in 2005-06. “The production of wheat for the year 2006-07 was 72.5 million tonnes compared to 69.4 million tonnes for 2005-06.”
23. 23. Condensation Helps in condensing mass of data in to few significant figures. Statistical methods present a meaningful overall information from mass of data. Example: Income position of people of India from a record of individual incomes of the entire population. (Per capita Income)
24. 24. Comparison Unless figures are compared with others of same kind they are often devoid of any meaning. Example: The production of rice in 2009-10 is likely to be 100 million tonnes as compared to 96 million tonnes in 2008-09.
25. 25. Formulation & TestingHypothesis Statistical methods are helpful in formulating and testing hypothesis & to develop new theories. Example: Hypothesis like whether chloromycetin is effective in curing typhoid. Whether students have benefitted from the extra coaching.etc. Technique: Chi-square Test
26. 26. Prediction Plans & policies of organisations are invaribly formulated well in advance of the time of their implementation. Statistical methods provide helpful means for forecasting future events. Example: How much cement should be produced by a cement company in coming year. Technique: Simulation
27. 27. Formulation of Policies Statistics provide the basic material for framing suitable policies. Example: Data about population- its distribution by age & sex, rate & growth of it. Migration, area etc. helps in determining the future needs such as food, clothing, housing, education, recr eational facilities, water, electricity, transportati on, system etc.
28. 28. Applications of Statistics
29. 29. Statistics & the State Since ancient times the ruling kings chiefs have relied on statistics in framing suitable military and fiscal policies. Eg. crimes, military strength, population, taxes etc. Today all ministers and departments of govt. (Finance, Transport, Defence, Railway, Food Commerce, Post & Telegraph, or Agriculture, etc.) depend heavily on factual data for their efficient functioning.
30. 30. Statistics & Business With growing size & ever increasing competition the problems of the business are becoming complex & they are using more & more statistics in decision making. Business activities can broadly grouped in to Production, Purchase, Finance, Personnel, Accounting, Market & Product Research, Quality Control. Each & every area is rely on statistics for their effective functioning.
31. 31. Statistics & Economics In the year 1890 Prof.Alfred Marshall the renowned economist observed that “ Statistics are the straw out of which I, Like every other economist, have to make bricks.’’ Economics is concerned with Production, Distribution, Consumption, saving & investment of income. Example: What to produce, how to produce, and for whom to produce – to answer these questions we need a lot of statistical data in absence of which it is not possible to arrive at correct decision. Statistics of production help in adjusting the supply to demand.
32. 32. Statistics & Economics Statistics of consumption enable us to find out the way in which people of different strata spend there income. To solve the problems of rising prices, growing population, unemployment, poverty etc. one has to rely on statistics. It plays role not only in formulating of economic policies but also evaluating their effects. We use statistics in Measurement of Gross national product, Input output analysis, money & banking, Consumer finance, Public Finance, business cycles,Competition, oligopoly & monopoly, comparison of market prices, cost & profit of individual firms, prices & Population etc.
33. 33. Statistics & Physical Sciences Astronomy Metrology Geology Physical Sciences Engineering Physics Chemistry
34. 34. Statistics & Natural Sciences Statistical techniques are proved very useful in the study of natural sciences. Like: Biology, medicine, zoology, botany etc. Example: In diagnosing the correct disease the doctor has to rely on data like body temperature, pulse rate, BP etc. Similarly in judging the efficacy of a particular drug for curing a disease experiments have to be conducted and the success or failure would depend upon the number of people who are cured after using a drug.
35. 35. Statistics And Research Most of the advancement in knowledge has taken place because of experiments conducted with the help of Statistical methods. Example: Experiments about crop yields & different types of fertilizers and different types of soils or the growth of animals under different diets and environments are designed and analysed with the help of statistical methods. Statistics affect research medicine & public health. We can not complete our research work without statistics.
36. 36. Limitations of Statistics Statistics does not deal with individual measurements. Statistics only deals with Quantitative Characteristics. Statistical results are true only on an average. Statistics is only one of the methods of studying a problem. Statistics can be misused.