The study of introductory Statistics is a Set of concepts, rules and procedures that help us to organize the numerical data in form of tables, graphs etc. It enables us to understand the statistical techniques to process it and make proper decisions. We can say that statistics is the study of the collection, organization, analysis and predictions done on the data. It helps us to design the surveys and experiments that are to be performed on the data for the purpose of interpretation of the given records. Statistical tests are commonly used in quantitative research. The purpose of introduction to mathematical statistics is to provide a brief introduction to Data Analysis, with an emphasis on statistics used in the social sciences. Introduction to statistics includes the basic study of the statistical data. |

Now statistics has completely changed and it has vast scope which involves lot of concepts. In modern times it is related to both the Sets of the collected information which are the temperature records, and the analytical work. Analytical work needs a very important thing that is Statistical Inference.

The statistical activities always use models which are expressed by the Probabilities. To create a theoretical frame for these models one must have the knowledge about Probability Theory.

There are so many concepts and theories of statistics that are very much used in science. It involves the designing of the experiments. It also consists of all the methods and approaches which are required for the statistical inference for example Bayesian inference.

Brief history of statistics is given below-

In 18

^{th}century, the term statistics meant the systematic collection of economical and demographic data. In the 19

^{th}century; it was extended to include all the disciplines and methods which are concerned with processing of data.

The processing of data involves the collection, summary, and analysis of data. Today the statistics is everywhere even in business, government, in all the fields of science. So we can say that it is a part of the mathematical science for example it is used in operations research, computer science etc. Statistics is now overlapping the computer science because it concerns with the data and information.

The basic steps utilized for a statistical experiment are:

1. Planning the research, which includes finding the number of replicates of the studies conducted.

2. Designing of the experiment to be performed. It includes primary analysis of experimental data.

3. Performing the experiment and then analysis of the data to be conducted which is to be carried by following the experimental protocol.

4. Examining of the data set in the secondary analysis; this finally helps to perform new hypotheses and to conduct future study of the experiment performed.

5. Final documentation and presenting of the data is performed in order to get the final output of the analysis which has been conducted on the raw data. Statistical sampling is the process of selecting data like age, people, and, organizations from a group of population of Interest in order to generalize the result. We begin with defining some of the terms used for Statistics and sampling. Whenever we collect any sample, usually we get some responses. So we can say a response is the specific value, which we get as a statistics sampling unit.

We have a statistical distribution method to find the population parameter from statistics and sampling.

The cost of Census being high, the survey of the entire population is not possible. So to lower the cost, to come at the conclusion faster and to improve the quality and accuracy of data, we use the sampling of the data.

Statistical Sampling can be done by different methods:

a) Direct Personal Investigation

b) Indirect Oral Investigations

c) Information from local agents and correspondents

d) Mailed Questionnaires and schedules

e) Drafting of the questionnaire.

A sound structure of investigation is based on systematic data sampling. Data is generally classified in two groups: Primary Data and Secondary Data

Primary Data is the data which is collected for the first time and is in the original form. This data is basically collected by the field workers and the investigators. This data is collected by the authorities who actually require the data

Secondary Data is that type of data which is collected and published by one organization and it is further used by another organization. So we conclude that the secondary data becomes primary data for the first organization and the same data becomes the secondary data for the organization. The same data is called Primary and on other hand it is termed as secondary, which takes the data from another source which has actually collected the data.

Primary data is the original collected data while the secondary data is taken from other agencies. Collecting primary data is more time consuming and so more expensive in comparison to the secondary data. So when we are using the primary data, the data is collected for a particular study for which it has been collected. Thus no special precautions are required to use this data.

To conduct the survey for the Data Collection, Proper planning of the statistical survey must be done and we must remember the following things:

1. The purpose of the data collection must be clear.

2. The Scope of the survey must be clear before the conduct of the survey. This explains what aspect are to be covered in the survey in order to achieve the given objectives.

3. Presentation of the dummy reports is done at the time scope of the survey is not clearly known to the person allotting the task or to the companies entrusted the task.

4. Laying down the hypothesis is another step to be considered. The hypothesis can be framed on the sample data by the survey agency.