Arithmetic
Additive Identity
Associative Property
Averages
Brackets
Closure Property
Commutative Property
Conversion of Measurement Units
Cube Root
Decimal
Distributivity of Multiplication over Addition
Divisibility Principles
Equality
Exponents
Factors
Fractions
Fundamental Operations
H.C.F / G.C.D
Integers
L.C.M
Multiples
Multiplicative Identity
Multiplicative Inverse
Numbers
Percentages
Profit and Loss
Ratio and Proportion
Simple Interest
Square Root
Unitary Method
Algebra
Algebraic Equation
Algebraic Expression
Cartesian System
Linear Equations
Order Relation
Polynomials
Probability
Standard Identities & their applications
Transpose
Geometry
Basic Geometrical Terms
Circle
Curves
Angles
Define Line, Line Segment and Rays
Non-Collinear Points
Parallelogram
Rectangle
Rhombus
Square
Three dimensional object
Trapezium
Triangle
Quadrilateral
Trigonometry
Trigonometry Ratios
Data-Handling
Arithmetic Mean
Frequency Distribution Table
Graphs
Median
Mode
Range
Home >> Frequency Distribution Table >> Grouped Frequency Distribution >>

Grouped Frequency Distribution

Grouped Frequency Distribution

Before you understand this concept, you are advised to read:

What is Frequency Distribution Table ?

As you know that data organized in the form of frequency distribution table helps us to read it easily. And also we could drive answers from it more quickly.

But sometimes the raw data received is very long and lengthy that if we prepare a frequency distribution table, the table will be very long and also it is in-convenient to draw result from such a long table.

Example : In a class of 30 students, following numbers represents weight of these students:
30, 31, 51, 35, 40, 39, 42, 43, 36, 49, 44, 33, 37, 47, 52, 38, 32, 50, 39, 40, 45, 46, 53, 35, 31, 41, 51, 33, 46, 53

Now, you can observe that if we prepare a simple Frequency Distribution Table, it will be very long and it will inconvenient to find answer from this. So, for this we put the data in groups and make a Grouped Frequency Distribution Table

Groups (Weight in Kg) Frequency (No. of Students)
30 35 6
35 40 7
40 45 6
45 50 5
50 55 6
Total 30


Hence, from the above grouped frequency distribution table we can conclude that maximum students comes in weight category of 35 40

The Groups i.e. 30-35, 35-40, 40-45, 45-50, 50-55 all are known as Class Intervals

In every Class interval, there is one Lower Class Limit and one Upper Class Limit i.e.

In 30 35: 30 is lower class limit and 35 is upper class limit
In 35 40: 35 is lower class limit and 40 is upper class limit
In 40 45: 40 is lower class limit and 45 is upper class limit
In 45 50: 45 is lower class limit and 50 is upper class limit
In 50 55: 50 is lower class limit and 55 is upper class limit

The difference between the Upper Class Limit and Lower Class Limit is called width or size of Class Intervals. We must remember that width of Class Intervals should be same in the entire table. As you can observe in the above example that the Width of Class Interval is same, i.e. 5 in each case.

Also, you will observe that few observations are same among different class intervals i.e.

35 is present in two Class intervals (30-35 & 35-40)
40 is present in two Class intervals (35-40 & 40-45)
45 is present in two Class intervals (40-45 & 45-50)
50 is present in two Class intervals (45-50 & 50-55)

So, will preparing the table, we cannot put entry of common observation in two class interval. Doing this leads to incorrect results.

Hence, common observation entry is done in higher class interval only, i.e.

35 is to be entered in class interval of 35-40 and not in 30-35
40 is to be entered in class interval of 40-45 and not in 35-40
45 is to be entered in class interval of 45-50 and not in 40-45
50 is to be entered in class interval of 50-55 and not in 45-50


Follow us on :

Terms & Conditions

All rights reserved