This presentation discusses frequency distribution graphs. It provides examples of constructing frequency distribution tables and calculating class midpoints and cumulative frequencies. The key graphs for representing frequency distributions are described as histograms, frequency polygons, and cumulative frequency curves for continuous or quantitative data. Bar charts, line graphs and pie charts are also introduced as options to display grouped or ungrouped categorical data. Examples of each type of graph are included.

1. Presentation on
Frequency Distribution
Graphs

2. Presenters
Name ID
Tirtha Mondal 133-15-2926
Nabila Hossain Asha 133-15-2890
Tonmuy Kundu 133-15-2976
Sharmin Taslim 133-15-2937
Naziya Farha 133-15-3005

3. Frequency Distribution
A frequency distribution is the organization of raw data in
table from, using classes and frequency.
 The number of miles that the employees of a large
department store traveled to work each day
1 2 6 7 12 13 2 6 9 5
18 7 3 15 15 4 17 1 14 5
4 16 4 5 8 6 5 18 5 2
9 11 12 1 9 2 10 11 4 10
9 18 8 8 4 14 7 3 2 6

4. Some Important terms
 Class limit: The class limits are the lowest and the highest
values that can be included in the class.
 Class interval: The class interval is obtained by subtracting
the lower limit of a class from the lower limit of the next
class. The class intervals should be equal. It is denoted
here by I
 Class Frequency: The number of observations in each
class. It is denoted here by f.
 Class Midpoint: A point that divides a class into two equal
parts. This is the average of the upper and lower class

5. Construction of frequency distribution
Example:
Here is some Ungroup data on the minimum minutes
spending for Reading Newspaper of 30 People.
15, 23, 19, 15, 18, 23, 14, 20, 13, 20, 17, 12, 20, 13, 21, 18,
29, 17, 18, 10, 26, 15, 14, 17, 30, 23, 12, 27, 16, 24.
Organizing the data into a frequency distribution
Step One: First arranging the data into ascending order.
Then we get the data as:
10, 12, 12, 13, 13, 14, 14, 15, 15, 15, 16,17, 17, 17,18, 18,
18, 19, 20, 20, 20, 21, 23, 23, 23,24, 26, 27, 29, 30.

6. Step Two: Decide on the number of classes using the formula
Where, k=Minimum number of classes
n=Number of observations
There are 30 observations so n=30. Therefore, k=5
Step Three: determine the class interval or width using the formula
Constracting Frequency Distribution Table.
Class Interval Tally Frequency, f
10 up to 14 5
14 up to 18 IIII 9
18 up to 22 III 8
22 up to 26 IIII 4
26up to 30 IIII 4

7. Class Midpoint: find the midpoint of each Class, use
the following formula:
Class Upper limit + Class lower limit
2
Class Interval Class Midpoint Frequency, f
10 up to 14 12 5
14 up to 18 16 9
18 up to 22 20 8
22 up to 26 24 4
26up to 30 28 4

8. Cumulative Frequency Distribution
A Cumulative Frequency Distribution is used to
determine how many or what proportion of the data
values are below or above a certain value.
Cumulative Frequency
Less Than MethodMore Than Method

9.  More Than Method
Class Interval Upper Limit Frequency, f Cumulative
Frequency
10 up to 14 14 5 5
14 up to 18 18 9 14
18 up to 22 22 8 22
22 up to 26 26 4 26
26up to 30 30 4 30
Class Interval Lower Limit Frequency, f Cumulative
Frequency
10 up to 14 10 5 30
14 up to 18 14 9 25
18 up to 22 18 8 16
22 up to 26 22 4 8
26up to 30 26 4 4
 Less Than Method

10. Graphs
Group Data Ungroup Data
For Continuous data or
quantitative variables:
The three commonly used
graphic forms are
Histograms
Frequency Polygons
Cumulative Frequency
Curve.
 Line graphs
 Bar Chart
 Pie Chart

11. Histogram
A Histogram is a graph in which the class midpoints or
limits are marked on the horizontal axis and the class
frequencies on the vertical axis. The class frequencies
are represented by the heights of the bars and the bars
are drawn adjacent to each other.

12. Frequency Polygons
A Frequency Polygon consists of line segments connecting
the points formed by the class midpoint and the class
frequency.
0
2
4
6
8
10
12 16 20 24 26
Class Midpoint
Frequency

13. Bar Chart
25
7
12
17
0
5
10
15
20
25
30
Sukrabad Mirpur Mohammadpur Dhanmondi
NUMBEROFSTUDENT
AREA
Student’s Living Area

14. Line graphs
1990 1995 2000 2005 2010 2015
Female 5 8 12 17 22 29
Male 13 15 19 25 32 38
Total 17 19 23 27 33 41
17 19
23
27
33
41
13
15
19
25
32
38
5
8
12
17
22
29
% of Education by Year In Bangladesh
Total Male Female

15. Pie Chart
CSE
28%
EEE
17%
BBA
11%
Others
44%
DIU Student
CSE EEE BBA Others