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# Basic Statistics for Commerce ## Introduction The views commonly held about statistics are numerous but often incomplete. It has different meanings to different people depending largely on its use. For example: - For a cricket fan, statistics refer to numerical information or data relating to...

# Basic Statistics for Commerce ## Introduction The views commonly held about statistics are numerous but often incomplete. It has different meanings to different people depending largely on its use. For example: - For a cricket fan, statistics refer to numerical information or data relating to the runs scored by a cricketer. - For an environmentalist, statistics refer to information on the quantity of pollution released into the atmosphere by all types of vehicles in different cities. - For the census department, statistics consists of information about the birth rate per thousand and the sex ratio in different states. - For a share broker, statistics is the information on changes in share prices over a period of time. ## Definition of Statistics Croxton and Cowden gave a definition of statistics. They have defined statistics in a singular sense. This definition also refers statistics as Statistical Method. According to Croxton and Cowden statistics was defined as a science of collection, presentation, analysis and interpretation of numerical data. This definition has pointed out four stages of statistical investigation, to which one more stage "organization of data" rightly deserves to be added. Accordingly, statistics was defined as the science of collecting, organizing, presenting, analyzing, and interpreting numerical data for making better decisions. ## Stages of Statistical Investigation 1. **Collection** 2. **Organization** 3. **Presentation** 4. **Analysis** 5. **Interpretation** ## Statistical Methods Statistical methods broadly fall into the following two categories: 1. **Descriptive Statistics:** Includes statistical methods involving the collection, presentation, and characterization of a set of data in order to describe the various features of that set of data. 2. **Inferential Statistics:** Includes statistical methods which facilitate estimating the characteristic of a population or making decisions concerning a population on the basis of sample results. ## Types of Data The collected data are of two types: 1. **Qualitative data**: When the data are classified according to some qualitative phenomena which are not capable of quantitative measurement like honesty, beauty, employment, intelligence, occupation, sex, literacy, etc. are termed as qualitative data. 2. **Quantitative data**: When the data are classified on the basis of a numerical measure like weight, height, temperature, etc. ### Qualitative Data The qualitative phenomena under study are known as Attributes. For example: - **Population:** has two classes like, presence and absence, male and female, honest or dishonest, employed or unemployed, beautiful or not beautiful is called dichotomous attribute. ### Quantitative Data Phenomenon under study is known as variables. Variables are of two kinds: 1. **Continuous variables**: Those variables which can take all possible values are termed as continuous variables. For example: The age of students can take all possible values (as seconds, etc.), within a certain range. 2. **Discrete variables**: Those variables which can take only specific distinct values are termed as discrete (discontinuous) variables. For example: Family size. ## Classifying Populations 1. Populations can be classified into more than two groups, for example: genius, very intelligent, average intelligent, etc. 2. The population can be classified by sex into two classes, for example: male, female. 3. We can classify populations by attribute, like smoking smokers and non-smokers, or by religion, like Hindus, Non-Hindus, etc.