Dr Rohan Sharma

The measurement of central value is also known as average. For example we often talk about the average height or average life of an Indian etc.   Types of Average Arithmetic Mean, Harmonic Mean, Geometric Mean  (1) Individual Observation (2) Discrete Series (3) Continuous series (a) Simple Arithmetic Mean      Que. 1 Calculate the Arithmetic Mean-With Individual Series  Que. 2 Calculate the Arithmetic Mean-With Discrete Series Que. 3. Calculate the Arithmetic Mean-With Continuous Series Geometric Mean Que 1  Que 2 Geometric Mean Discrete Series Geometric Mean  Continuous Series Harmonic Mean   Que 1  With Discrete Series Que 2  With Continuous Series                                                                              = 30/1.004                                                                                                                                                             =  29.88    

Census and Sample : Under the census data are collected for each and every unit of population on the other side sampling is simply the process of learning about the population on the basis of a sample The sampling can be grouped under two broad heads probability sample and non probability sample . where as probability sampling method are those in which every item in the universe has probability of being chosen for the sample. where as non-probability sampling method are those which do not provide every item in the universe with a known chance of being included in the sample.  1. Probability Sampling Method    (a) Sample Random Sampling : Lottery Method, Table of Random Number (b) Systematic Sampling: In it the first sample is selected randomely and generally followed by Kth students  K=N/n K= Sampling Interval , N= Universe Size and n= Sample Size  for example in a class 100 students with roll no from 1 to 100. It is decided to take a sample of 10 students. Use systematic sa

One of the best method through which statistical result can be displayed or presented is through diagram and graphs. We can found it in the different news papers, magazines, journals, etc. Diagram are more attractive to the eyes and are better suited for the publicity and propaganda. In fact these days it is difficult to find any research work without the diagram support. On the other side Graphs we generally make use of graph paper, In other words a graph represent mathematical relationship between two variables. Types of Diagrams: (1) One -Dimensional Diagram or Bar Diagram  (a) Simple Bar Diagram : In the simple bar diagram is used to represent only one variables. For example the figure o sales, production, population etc. The sales figure of Dell Co. as below:     (b) Sub-divided bar diagram : In a sub-divided bar diagram each bar represent the magnitude of a given phenomenon is further sub divided in its various components. For example the  students scored different marks in di

  Source of Primary Data and Secondary Data:   Primary Data   is the first hand information which is original in character and are generated in character and are generated in large number surveys. conducted mostly by government and also by some individuals, institutions and research bodies. Data which are not originally collected but rather obtained from published (News paper, Magazines, Reports and official publications, books etc.)  or unpublished sources are known as  Secondary data .    Methods of collecting Primary Data:     (1)  Direct personal Interview : Under this method of collecting data, there is a face to face contact with the person from whom the information is to be obtained.    (2)  Indirect Oral Interview : Under this method of collecting data, the investigator contacts third parties called witnesses.  (3)  Information from Correspondent : Under this method, the investigator appoints local agents or correspondents in different places to collect information. (4) 

  (1) Statistics does not deal with individual measurement  (2) statistics deals only with quantitative data (3) Statistics is only one of the methods of studying a problem (4) Statistics can be misused

   (1) Statistics and Business (2) Statistics and Economics (3) Statistics and Research (4) Statistics and other Use

  ( 1)   Statistics are numerically expressed. (2) It is collection of aggregate of fact. (3) Data are collected in systematic order. (4) It should be comparable to each other. (5) Data are collected for a some purpose.

Definition :  Boddington define statistics as  "the science of estimates and probabilities" Croxton and cowden have given simple and concise definition of statistics. In their views   "Statistics may be defined as the collection, presentation, analysis and interpretation of numerical data" According to the above definition, the five stages in statistics are discussed as below: (1) Collection of Data:  The collection of data is the first step in the a statistical investigation. The data can be collected from any source it may be available from the existing published source or unpublished source or it can be collected by the investigator himself. The first hand collection of data is the most difficult task. (2) Organisation of Data:  The   collected data can organized in the tabular form. The purpose of tabulation is to arrange the data in columns and rows so that there is absolute clarity in the data presented. Example as below:  (3)   Presentation of Data: