Graphical Representation of data detail.pdf

These slides describe detail topic graphical representation. I hope students get more benefits about it.

1. Graphic Presentation of Data
Statistical tables contain numeric information, which are usually not an attractive
way of presenting the data, because many people find it difficult to get a clear picture
from the numeric data. A more attractive method of presenting the data is draw diagrams
and graphs.

2. Diagram or Graph: A diagram or graph is a two-dimensional geometric representation
of data according to some visualization technique. Sometimes, the technique uses a
three-dimensional visualization which is then projected onto the two-dimensional
surface. There are various types of diagrams. Few of them are considered below.
Simple Bar Chart/ Diagram: A simple bar diagram is made to represent
geographical, historical and the qualitative data. The vertical or horizontal bars are
made with height or length proportional to the values that they represent. Bar charts are
used for plotting discrete data. Some examples of discontinuous data include “shoe size” or
“eye color” etc. Each bar is separated from others by a suitable space.
Example: Draw simple bar diagram for the data below.
Years Profits in Millions
1989 10
1990 12
1991 18
1992 25
1993 40


Pofit(million Rs)
45
40
35
30
25
20 Profit(million Rs)
15
10 5
0
1989 1990 1991 1992 1993


Figure: Simple Bar Cha

3. Multiple Bar Charts/ Diagrams: The multiple bar diagrams are made when the data
are in the form of different groups and each group contain two or more pieces of
information. Adjacent bars are made representing various groups. Each multiple bar is
separated from others by a suitable space. Imports and exports of a country from January
to December, birth and death rates of a country over a number of years can be shown by
multiple bar diagram. Example: Draw a suitable diagram for the data of birth rates
and death rates of following countries.
Country Birth rate Death rate
Pakistan 45 15
India 40 16
England 10 10
Egypt 35 12
Japan 10 10


50
45
40
35
30
25
20
15
10
5
0
Pakistan India England Egypt Japan







Birth rate
Death rate






Figure: Multiple Bar Chart

4. Sub-Divided or Component Bar Chart: Component bar charts are made when
are interested to make comparison of the totals of some groups of data and the comparison
within group is also desired. Each bar represents the total of some components and each
component is shown as a proportional part of the bar. Each bar is separated by a suitable
space between them.

Example: Given below are the number of sheep and goats (in hundreds) in different
divisions during the year 1982-83. Draw a component bar chart.


Division No of sheep
(00)
No of goats
(00)
Total
Bahawalpur 667 1583 2250
D.G.Khan 413 768 1181
Faisalabad 1311 3122 4433
Gujranwala 1495 2265 3760
Lahore 4262 5777 10039
Multan 1434 3778 5212
Rawallpindi 372 3415 3787
Sargodha 448 1048 1496