Pie-Diagrams
The Pie diagrams are very popularly used in practice to represent percentage breakdowns. For e.g., with the help of a pie diagram we can represent how the expenditure of the government is distributed in various heads like irrigation, agriculture, industry, transport, defense, etc, similarly through a pie diagram we can represent how the expenditures incurred by an industry are divided under different heads like wages, raw materials, and salaries, selling and distribution expenses, etc. the pie chart is so called as the entire graph looks like a pie, and the components resemble slices cut from pie.
In laying out the sectors for pie chart, it is desirable to follow some logical arrangement or sequence. It is common practice to start the largest component sector of pie diagram at 12 clock position on the circle. Unusually the other component sectors are placed in the clockwise succession in descending order of magnitude, except for catch-all components like miscellaneous and all others which are shown last, contrast with the adjacent sectors.
Illustration: - Draw a pie diagram for the following data of sixth five-year plan public sector outlays.
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Agriculture and rural development
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12.9%
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Irrigation etc,
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12.5%
|
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Energy
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27.2%
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Industry and minerals
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15.4%
|
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Transport communication, etc,
|
15.9%
|
|
Social services and others
|
16.1%
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Solution: - the angle at the centre is given by
Percentage outlay / 100 x 360 = percentage outlay x 3.6
Computation for pie diagram
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Sector
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Percentage
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Angle outlay
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agricultural and rural development
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12.9
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12.9 x 3.6 = 46
|
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Irrigation etc,
|
12.5
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12.5 x 3.6 = 45
|
|
Energy
|
27.2
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27.2 x 3.6 = 98
|
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Industry and minerals
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15.4
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15.4 x 3.6 = 56
|
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Transport, communication etc.
|
15.9
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15.9 x 3.6 = 57
|
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Social services and others
|
16.1
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16.1 x 3.6 = 58
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Total
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100.1
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360
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