Pie Chart

Pie Chart is a pictorial representation of the data. It uses a circle to represent the data and hence is also called a Circle Graph. In a Pie Chart, we present the data by dividing the whole circle into smaller slices or sectors and each slice or sector represents specific data.

A circle subtends a total of 360Â° angle at the center of the circle. If we want to represent various things in a Pie chart we first find the central angle of that measurement and then make a sector for that measurement. The best real-life example of a circle graph or a pie chart is Pizza in a pizza each slice of the pizza can be used to represent various data.

In this article, we will learn about Pie Charts, Steps to Create Pie Charts, Examples, and Others in detail. The image added below shows a pie chart.

What is Pie Chart?

A pie chart is a pictorial or graphical representation of data in chart format. A pie chart uses a circle or sphere to represent the data, where the circle represents the entire data, and the slices represent the data in parts. Pie chart is one of the easiest ways to present and understand the given data, and pie charts are used very commonly. For example, pie charts are used in excel very often.

Pie Chart Definition

There are different ways of data representation. A pie chart is one of the types of charts in which the data is represented in a circular shape. The pie chart circle is further divided into multiple sectors/slices; those sectors show the different parts of the data from the whole. Pie charts, also known as circle graphs or pie diagrams, are very useful in representing and interpreting data. The data can be compared easily with the help of a pie chart. Below is an example of a pie chart explained in detail.

Pie Chart Examples

Let’s take a look at an example for a better understanding of pie charts. In a class of 200 students, a survey was done to collect each student’s favorite sports. The pie chart of the data is given below:

Since the pie chart is provided and the total number of students is given, we can easily take the original data out for each sport.

• Cricket = 17/100 Ã— 200 = 34 students
• Football = 25/100 Ã— 200 = 50 students
• Badminton = 12/100 Ã— 200 = 24 students
• Hockey = 5/100 Ã— 200 = 10 students
• Other = 41/100 Ã— 200 = 82 students

The original data for the pie chart shown above is given below:

Sport

Number of Students

Cricket

34

Football

50

24

Hockey

10

Other

82

Pie Chart Formula

The total value or percentage of the pie is 100% always. Here it contains different sectors and segments in which each sector or segment of the chart corresponds to a certain portion of the net or total percentage (or data). The total or sum of all the data can be summed up to 360 degrees.

• Converting the data into degrees on a pie chart. The formula for a pie chart can be summed up as:

(Given Data / Total Value of Data) Ã— 360Â°

• Calculating the percentage of each sector from degrees in a pie chart.

To work out with degrees in a pie chart, we need to follow the following steps:

• First, we need to measure every slice of the chart.
• Then we need to divide it by 360Â°.
• Finally, multiply the obtained result by 100.

The pi chart formula is given below:

(Frequency)/(Total Frequency) Ã— 100

Calculating Number of Sectors on a Pie Chart

To calculate the total number of slices or sectors on a pie chart, we need to multiply the sector’s percentage by the total value of the data and finally divide the result by 100.

Steps to Construct Pie Chart

We will learn how to create a pie chart step by step with the help of an example. A teacher surveyed a group of students to see what is their favorite hobby of each student. Let’s take a look at the pie chart example with an explanation. The data collected is listed as follows:

Hobbies

Number of students

Singing

16

20

Dancing

10

Painting

30

Others

24

Now we will see how to construct a pie chart step by step.

Step 1: The first step requires us to write down the available data in tabular form as follows:

Singing

Dancing

Painting

Others

16

20

10

30

24

Step 2: Now find the sum of all the given data. Here, the Sum of All Data = (16 + 20 + 10 + 30 + 24) = 100

Step 3: Now, calculate the percentage of each sector. We need to divide each sector value by the sum or total and then multiply it by 100.

Singing

Dancing

Painting

Others

(16/100) Ã— 100

= 16%

(20/100) Ã— 100

= 20%

(10/100) Ã— 100

= 10%

(30/100) Ã— 100

= 30%

(24/100) Ã— 100

= 24%

Step 4: Next step is to calculate the degrees corresponding to each slice. The values can be calculated as:

Central Angle of Each Component = (Given Data / Total Value of Data) Ã— 360

Hence, The values are as follows:

Singing

Dancing

Painting

Others

(16/100) Ã— 360

= 57.6

(20/100) Ã— 360

= 72

(10/100) Ã— 360

= 36

(30/100) Ã— 360

= 108

(24/100) Ã— 360

= 86.4

Step 5: Now, with the help of a protractor, we will measure each angle from a single point or central point and draw the circle’s sectors. The resultant pie chart will be:

Interpreting Pie Chart

In order to interpret a pie chart, the first thing to notice is the data presented in the pie chart. If the data is given in percentage, it should be converted accordingly in order to analyze and interpret the data. Let’s take a look at an example in order to learn how to interpret pie charts.

Example: In a survey done among 300 people, it was observed which type of genre each person prefers. The pie chart of the same is mentioned below. Analyze and interpret the pie chart accordingly to find the original data.

Solution:

While observing the pie chart, it came to notice that the data is present in percentage. Lets convert the data to obtain the original value.

• Number of people who like comedy = 20/100 Ã— 300 = 60 people.
• Number of people who like action = 25/100 Ã— 300 = 75 people.
• Number of people who like romance = 30/100 Ã— 300 = 90 people.
• Number of people who like drama = 5/100 Ã— 300 = 15 people.
• Number of people who like sci-fi = 20/100 Ã— 300 = 60 people.

Pie Chart is very useful for finding and representing data. Varous advantages of the pie chart are,

• Pie chart is easily understood and comprehended.
• Visual representation of data in a pie chart is done as a fractional part of a whole.
• Pie chart provides an effective mode of communication to all types of audiences.
• Pie chart provides a better comparison of data for the audience.

There are some disadvantages also of using pie charts and some of them are added below,

• In the case of too much data, this presentation becomes less effective using a pie chart.
• For multiple data sets, we need a series to compare them.
• For analyzing and Assimilating the data in a pie chart, it is difficult for readers to comprehend.

Uses of Pie Chart

Whenever a fraction or fractions are represented as a part of the whole, pie charts are used. Pie charts are used to compare the data and to analyze which data is bigger or smaller. Hence, while dealing with discrete data, pie charts are preferred. Let’s take a look at the uses of the pie chart:

• Pie charts are used to compare the profit and loss in businesses.
• In schools, the grades can be easily compared using a pie chart.
• The relative sizes of data can be compared using a pie chart.
• The marketing and sales data can be compared using a pie chart.

Pie Chart Examples

Example 1: The given pie chart shows the subject of interest of each student in a class.

Answer the following question concerning the given pie diagram.

1. If 30 students’ subjects of interest are history, how many total students were surveyed?
2. Which subject is liked the most?
3. Which subject is disliked the most?

Solution:

1. According to the given question, 8% of the total number of students is 30. i.e. (8/100) x Total = 30

Therefore, Total = 30 x (100/8) = 375

Hence 375 students were surveyed.

2. According to the given pie chart, science is liked the most.

3. According to the given pie chart, history is disliked the most.

Example 2: For a science camp, students from different states have enrolled. Construct a pie chart for the given table:

States

Number of students

West Bengal

10

Assam

5

5

Gujarat

10

Karnataka

10

Solution:

Step 1: The first step requires us to jot down the available data into tabular form as follows:

West Bengal

Assam

Gujarat

Karnataka

10

5

5

10

10

Step 2: The next task is to calculate the sum of all the given data.

Here, the Sum of All Data = (10 + 5 + 5 + 10 + 10) = 40

Step 3: Now, the next task is to calculate the percentage of each sector. We need to divide each sector value by the sum or total and then multiply it by 100.

West Bengal

Assam

Gujarat

Karnataka

(10/40) Ã— 100

= 25%

(5/40) Ã— 100

= 12.5%

(5/40) Ã— 100

= 12.5%

(10/40) Ã— 100

= 25%

(10/40) Ã— 100

= 25%

Step 4: Next step is to calculate the degrees corresponding to each slice. The values can be calculated as:

West Bengal

Assam

Gujarat

Karnataka

(10/40) Ã— 360

= 90

(5/40) Ã— 360

= 45

(5/40) Ã— 360

= 45

(10/40) Ã— 360

= 90

(10/40) Ã— 360

= 90

Step 5: Now, with a protractor’s help, we will measure each angle from a single point or central point and draw the circle’s sectors. The resultant pie chart will be:

Example 3: A pie chart is divided into four parts, and the values are given as x, 3x, 4x, and 4x. Find the value of x in degrees.

Solution:

As it is known that a pie chart has 360Â°. Therefore, if all the angles are added, it will give 360Â°.

x + 3x + 4x + 4x = 360Â°

12x = 360Â°

x = 30Â°

Practice Questions on Pie Charts

Q1. Students selected for ISRO visit from various states are given in the table below. Represent them in a pie chart.

States

Number of students

West Bengal

7

Assam

6

3

Gujarat

10

Karnataka

4

Q2. Marks scored by Kabir in an exam in various subject is shown in the table below show a pie chart representing the same.

Subjects

Marks

Mathematics

99

Physcis

98

Chemistry

98

English

95

Computers

97

FAQs on Pie Chart

1. What is a Pie Chart?

Pie chart is the visual representation in which a circle graph is used to represent the values according to numbers, percentages, and degrees. The circle represents the entire data, and the sector or slices are used to represent values that are parts of the data.

2. What is Formula for a Pie Chart?

To calculate the percentage of the given data, the formula used:

• (Frequency Ã· Total Frequency) Ã— 100

Converting data into degrees:

• (Given Data Ã· Total Data) Ã— 100

3. How to Create a Pie Chart?

Following are the steps that should be followed in order to create a pie chart:

Step 1: Add all values to find out the total data.

Step 2: In order to convert them in percentages, divide each value with the total data and multiply them with 100.

Step 3: Use the formula to find the degrees of each percentage value: (frequency Ã· total frequency) Ã— 100.

Step 4: Now, draw a circle and using a protector, draw the sector based on the degree obtained w.r.t. the values.

4. What are Examples of Pie Chart?

There are many examples of pie chart as pie chart is often used for visual representation. Following are some of the real-life examples:

• Representation of marks obtained by students.
• The marketing and sales data is obtained by using a pie chart.
• The profit and loss endured by a business can be represented by a pie chart.

5. What is Polpulation Pie chart?

The population pie chart is the pie chart that represent the population of any area and the population pie chart of the world is shown in the image added below,

6. What are Uses of Pie Chart?

Pie charts are used for various purposes and various uses of pie chart are,

• It is used to represent various types of data.
• It is used to show data of various demographics.
• It is used to represent various objects of sales, marketing, and others, etc.

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