Question

Solve the following question:
Electricity used by the farmers during parts of a day for irrigation is as follows:
Draw pie diagram.

Part of a day	Morning	Afternoon	Evening	Night
Percentage of electricity used	$30$	$40$	$20$	$10$

Answer 1

First we calculate the total percentage of the electricity used. Then we take that and multiply the percentage of each time with the angle of the circle to obtain that certain angle for that particular slot. Using those angles, we construct a pie-chart with the angle measures.

Complete step-by-step solution:
Given are the electricity percentages used in each part of the day by the farmers.
Let us break it as given below;
Morning $= 30$
Afternoon $= 40$
Evening $= 20$
Night $= 10$
Total percentage or total electricity used $= 100$
Now, to draw a pie chart, we need to find the central angles of consumption of electricity in all the parts. Since we draw a pie chart in the form of a circle, the total angle is ${360^ \circ }$
We take the parts out of ${360^ \circ }$as given below;
The central angle for the consumption of electricity in the morning $= \dfrac{{30}}{{100}} \times 360$
Cancelling out the zeros and reducing the above term, we get;
$108$
The central angle for the consumption of electricity in the afternoon $= \dfrac{{40}}{{100}} \times 360$
Cancelling out the zeros and reducing the above term, we get;
$144$
The central angle for the consumption of electricity in the evening $= \dfrac{{20}}{{100}} \times 360$
Cancelling out the zeros and reducing the above term, we get;
$72$
The central angle for the consumption of electricity in the night $= \dfrac{{10}}{{100}} \times 360$
Cancelling out the zeros and reducing the above term, we get;
$36$
We got the angles to be distributed on the pie-chart as $108,144,72,36$ as morning, afternoon, evening and night respectively. We get the pie chart as shown below;

Note: We have to know about pie charts, a pie chart (or circle chart) is a circular statistical graphic, which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and area), is proportional to the quantity it represents. While it is named for its resemblance to a pie which has been sliced, there are variations on the way it can be presented. Pie charts are very widely used in the business world and the mass media. Pie charts can be replaced in most cases by other plots such as the bar chart, box plot, dot plot.