Class XI:Statistics [Ch-1 Introduction]

Introduction

What Is Statistics?

Statistics, in itself, is the collection and analysis of numerical data to arrive at specific inference.

1. Singular Statistics

The statistician Stephen Senn has defined it as ‘the science of quantitative reasoning’- of ways of thinking about and working with numerical facts and ideas.

2. Plural Statistics

A ‘statistic’ is a numerical fact, or a piece of numerical information or data, and collection of such things are called ‘statistic’ plural.

Scope Of Statistics

Statistics are numerical statements of facts capable of analysis and interpretation as well as study of the methods used in collection, organisation, presentation, analysis, and interpretation of numerical data.

Basic Relationship Between Economics And Statistics

When we study the basic problems facing a country, such as poverty, inequalities of income etc these studies require that we know more about Economic facts. Statistics help in the collection, organisation, presentation, analysis and interpretation of these economic facts.

Features Of Statistics 

1. It Consists Of Aggregates Of Facts:

In the plural sense, statistics refers to data, but data to be called statistics must consist of aggregate of certain facts.

For a data may amount to statistics it must be in the form of a set or aggregate of certain facts, viz. 50, 65, 70 Kgs. weight of students in a class or profits of a firm over different times etc. is liable to be affected by multiplicity of causes.

2. It Is Affected By Many Causes:

It is not easy to study the effects of one factor only by ignoring the effects of other factors. Here, the overall effect is taken and not of one factor only as in other natural sciences.

3. It Should Be Numerically Expressed:

A data to be called statistics should be numerically expressed so that counting or measurement of data can be made possible. Thus these data must contain numerical figures so that those may be called as numerical statements of facts.

4. It Must Be Enumerated Or Estimated Accurately:

As stated above, the statements should be precise and meaningful. If it is infinite or very large, even enumeration of data is impossible and a reasonable standard of accuracy may not be achieved. Example- we may measure the height of buildings in metres but we cannot measure the length of small things like bricks in the same unit of metre.

5. It Should Be Collected In A Systematic Manner:

Another characteristic of statistics is that the data should be collected in a systematic manner. A proper plan should be made and trained investigators should be used to collect data so that they may collect statistics.  So to get correct results the data must be collected in a precise manner.

6. It Should Be Collected For A Predetermined Purpose:

Before we start the collection of data, we must be clear with the purpose for which we are collecting the data. We may need some more relevant data to achieve the required purpose, which we would miss in the event of its ignorance.

If some person in the government duty is counting the vehicles passing through a road in a unit time is statistics, but same work done by any other person not related to this field, is not statistics because the former is doing it for the Government which wants to make it a four lane road-if needed.

7. It Should Be Capable Of Being Placed In Relation To Each Other:

Last but not least, the characteristics of the statistics. If the figures collected are not comparable, in that case, they lose a large part of their significance.

For example- Heterogeneous data like sale of Rs. 20,000 result of 80% cases and mileage of 80 kms can never be placed in relation to each other and compared for analysis and interpretation which is the ulterior motive of the science of statistics.