(1) Statistics and Business (2) Statistics and Economics (3) Statistics and Research (4) Statistics and other Use
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(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
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 The data can be collected from any source it may be available from the existing published source or unpublished source or it can be collected by the investigator himself.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:
( 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.
Range The range is the simple method of studying dispersion. It is defined as difference between the value of the smallest item and the value of largest item included in the distribution. Range= L-S L= Largest Item S= Smallest Item Coefficient of Range = L-S/L+S Que 1. Calculate Range and its coefficient Sol Range= L-S L = 250 S = 160 Range = 250-160 = 90 Coefficient of Range = L-S/L+S = 250-160/250+160 = 90/410 = 0.22 Quartile Deviation Sol Arrange in ascending order Que 2 Que 3 Mean Deviation: The mean deviation is also known as the average deviation. It is the average difference between the items in a distribution and the median or mean of that series Que 1 Que 2 Que 3 Standard Deviation: The standard deviation concept was introduced by Karl Person in 1823. The standard devia
The median is defined as the middle value in an distribution, it is important to keep a note that before to calculate median one should arrange the frequency in ascending or in descending order for example the income of five employees is 900, 950,1020, 1200 & 1280. The mid value is 1020. In the case of even number of series the income of six employees are 900, 950, 1020,1200, 1280, 1300. Now in the case of even values the middle values are 1020 and 1200 Median = 1020+1200/2 Median = 2220/2 Median = 1110 Q 1. Calculate median with Individual series Q 2. Calculate median with Discrete series Q 3. Calculate median with Continuous series Q 4. Calculate Quartiles, Decilesand & Percentile Assignment 1: DOS (14/5/21) Que 1 What is Primary data and Secondary Data and explain the difference between census and sampling Que 2 Cal GM from the following Data X f 260 46 180 10 220 8 230 20 120 12 200 4 Que 3 Cal HM from the f
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)
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