Page 1 - Lesson note -1 -Ch.14 Statistics( Introduction,Presentation of Data)

SAI International Residential school
Class –IX

Mathematics

Chapter-14: statistics

LESSON NOTES-1

Sub topics: Introduction, collection and presentation of data.

Introduction

Every day we come across a wide variety of information in the form of facts, numerical
figures, tables, graphs, etc.
These are provided by newspapers, televisions, magazines and other means of
communication. These may relate to cricket batting or bowling averages, profits of a
company, temperatures of cities, expenditures in various sectors of a five year plan,
polling results, and so on.
These facts or figures, which are numerical or otherwise, collected with a definite
purpose, are called data.
Our world is becoming more and more information oriented. Every part of our lives
utilizes data in one form or the other. So, it becomes essential for us to know how to
extract meaningful information from such data. This extraction of meaningful
information is studied in a branch of mathematics called Statistics.

“Statistics” in (i) singular form (ii) plural form?
The word statistics is used in both its singular and plural senses.

(i) In singular sense, statistics may be defined as science of collection, presentation,
analysis and Interpretation of numerical data.

(ii) In plural sense, statistics means numerical facts or observations collected with
definite purpose.

Some fundamental characteristics of statistics.

(1) Statistics are collected with definite purpose.
(2) Statistics are expressed quantitatively not qualitatively.
(3) Statistics in an experiment are comparable and can be classified into different
groups.