## History of Statistics

The word statistics is derived from the Latin word “status” or the Italian word “statista,” and meaning of these words… Click here to read more

From basic to higher mathematics

The word statistics is derived from the Latin word “status” or the Italian word “statista,” and meaning of these words… Click here to read more

The word statistics has three different meanings, which are discussed below: (1) Plural Sense (2) Singular Sense (3) Plural of… Click here to read more

Statistics, like many other sciences, is a developing discipline; it is not static. It has gradually developed during the last… Click here to read more

Statistics may be divided into two main branches: (1) Descriptive Statistics (2) Inferential Statistics (1) Descriptive Statistics Descriptive statistics deals… Click here to read more

Some of the important characteristics of statistics are given below: Statistics are aggregates of facts. Statistics are numerically expressed. Statistics… Click here to read more

The important limitations of statistics are: (1) Statistics laws are true on average. Statistics are aggregates of facts, so a… Click here to read more

(1) Statistics helps in providing a better understanding and exact description of a phenomenon of nature. (2) Statistics helps in… Click here to read more

Statistics plays a vital role in every field of human activity. Statistics helps in determining the existing position of per… Click here to read more

Constant A quantity which can assume only one value is called a constant. It is usually denoted by the first… Click here to read more

Statistical Data A sequence of observations, made on a set of objects included in the sample drawn from population, is… Click here to read more

The process of arranging data into homogenous groups or classes according to some common characteristics present in the data is… Click here to read more

The process of placing classified data into tabular form is known as tabulation. A table is a symmetric arrangement of… Click here to read more

(1) First the data are classified and then they are presented in tables, and classification and tabulation in fact go… Click here to read more

A statistical table has at least four major parts and some other minor parts. (1) The Title (2) The Box… Click here to read more

A frequency distribution is a tabular arrangement of data into classes according to size or magnitude along with corresponding class… Click here to read more

The following steps are involved in the construction of a frequency distribution. (1) Find the range of the data: The… Click here to read more

Construct a frequency distribution with the suitable class interval size of marks obtained by 50 students of a class, which… Click here to read more

Discrete data is generated by counting, and each and every observation is exact. When an observation is repeated, it is… Click here to read more

The total frequency of all classes less than the upper class boundary of a given class is called the cumulative… Click here to read more

We have discussed the techniques of classification and tabulation that help us organize the collected data in a meaningful fashion…. Click here to read more

A simple bar chart is used to represent data involving only one variable classified on a spatial, quantitative or temporal… Click here to read more

In a multiple bars diagram two or more sets of inter-related data are represented (multiple bar diagram faciliates comparison between… Click here to read more

A sub-divided or component bar chart is used to represent data in which the total magnitude is divided into different… Click here to read more

A sub-divided bar chart may be drawn on a percentage basis. To draw a sub-divided bar chart on a percentage… Click here to read more

A pie chart can used to compare the relation between the whole and its components. A pie chart is a… Click here to read more

Average “A single value which can represent the whole set of data is called an average”. If the average tends… Click here to read more

Arithmetic mean is the most commonly used average or measure of the central tendency applicable only in case of quantitative… Click here to read more

Example: The following data shows distance covered by $$100$$ people to perform their routine jobs. Distance (Km) $$0 – 10$$… Click here to read more

When calculating the arithmetic mean, the importance of all the items are considered to be equal. However, there may be… Click here to read more

Pros: It is rigidly defined It is easy to calculate and simple to follow It is based on all the… Click here to read more

The geometric mean is another measure of central tendency based on mathematical footing, like arithmetic mean. The geometric mean can… Click here to read more

The main properties of the geometric mean are: The geometric mean is less than the arithmetic mean, $$G.M < A.M$$… Click here to read more

Pros: It is rigidly defined and its value is a precise figure. It is based on all observations. It is… Click here to read more

Harmonic mean is another measure of central tendency and is also based on mathematics like arithmetic mean and geometric mean…. Click here to read more

Pros: It is based on all observations. It not significantly affected by the fluctuation of sampling. It is capable of… Click here to read more

Mode is the value which occurs the greatest number of times in the data. When each value occurs the same… Click here to read more

Advantages It is easy to understand and simple to calculate. It is not affected by extremely large or small values…. Click here to read more

Graphic Location of Mode Since mode is a positional average it can be located graphically by the following process: A… Click here to read more

Median is the most middle value in the arrayed data. It means that when the data are arranged, the median… Click here to read more

Median and other partition values can be located on the graph of the cumulative frequency polygon (Ogive Polygon). Suppose we… Click here to read more

There are three quartiles called the first quartile, second quartile and third quartile. The quartiles divide the set of observations… Click here to read more

Deciles Deciles are the partition values which divide the set of observations into ten equal parts. There are nine deciles:… Click here to read more

A modern student of statistics is mainly interested in the study of variability and uncertainty. In this section we shall… Click here to read more

For the study of dispersion, we need some measures which show whether the dispersion is small or large. There are… Click here to read more

Range Range is defined as the difference between the maximum and the minimum observation of the given data. If $${x_m}$$… Click here to read more

Quartile Deviation Quartile deviation is based on the lower quartile $${Q_1}$$ and the upper quartile $${Q_3}$$. The difference $${Q_3} –… Click here to read more

The mean deviation or the average deviation is defined as the mean of the absolute deviations of observations from some… Click here to read more

The standard deviation is defined as the positive square root of the mean of the square deviations taken from the… Click here to read more

Examples of Standard Deviation This tutorial covers some examples of standard deviation using all methods which are discussed in the… Click here to read more

Coefficient of Standard Deviation The standard deviation is the absolute measure of dispersion. Its relative measure is called the standard… Click here to read more