DATA HANDLING

INTRODUCTION

The word ‘data’ means collection of

information in the form of numerical figures,

or a set of given facts.

Visual representation of data will help us to

understand it better and remember the facts

easily.

Examples :

When some information is collected and presented randomly, then it is called raw data. - The marks obtained by 10 students of a class in a test are:

76, 83, 95, 100, 56, 32, 80, 67, 75, 46

A data classified into groups is called grouped data.

- The following table gives the data regarding the favourite game of 100 students of school:

Sports Cricket Football Tennis Badminton

No. of Students

40 30 25 5

ADVANTAGESof handling data in a systematic order

Data in raw form can be represented in the form of pictures and diagrams.

 It makes the given data attractive to the observer.

Also, it is easy to understand and to compare it with other information.

Representation of Numerical Data :

Pictograph

Bar graph Pie graph

PICTOGRAPH

Pictographs represent data through appropriate pictures. 

In pictographs, the same type of symbol or picture is used to represent the data. Each symbol is used to represent a certain value.

For example, one symbol may represent 25 students.

The following pictograph represents the number of students coming to a college by different means of transport:

Bus25 x 7 =

175

Bicycle25 x 4 =

100On foot

25 x 5 = 125

Example :

Distribution of cars in the month of July, August and September :

Bar Graph

A representation of data with the help

of bars or rectangles in a diagram is

called a bar graph or a bar diagram.

Each bar = one value of data, and

hence, there are as many bars as the

number of values in the data

Length/height of bar = value of

item,

Frequency Distribution Table

Grouping the raw data :

Each group is called a class interval Lower Class Limit

Upper Class Limit

Upper Class Limit – Lower Class Limit = Width/size of class interval

Frequency : no. of times a particular item appears with particular class interval

Fill up the rows with tally marks and will count the total number of tally marks in each group.

Number of tally marks in each group is listed in the frequency column.

Double Bar Graph

A graph showing two sets of data simultaneously is called a double bar graph.

 It is useful for comparing two sets of data.

Example : The following graph shows the strength of boys and girls in a school in different years: