Data interpretation of the pie chart is the representation of data in a circle that is divided into various sectors. These sectors are constructed in such a way that the area of each sector is proportional to the corresponding magnitude of the data represented by the sector.

**Some useful points in data interpretation of pie chart:**

- Here, different sectors in a pie chart are considered as component parts.
- In a pie chart component parts are expressed in 3 types.

- Either component values in percentages.
- The fractional ratio of respective total value given.
- Sector angle of respective total value given

- Since the pie chart is a circle and it has 360 degrees at its center which are equal to 100% of component values when added.
- 100% of component values represented on the pie chart are equal to 360 degrees angle of the pie chart.

100%=360 degrees

1%=3.6 degrees

So, when the percentage of component values is given they can be converted to a degree by multiplying each of the percentage values with 3.6 degrees.

**The formula for the angle of a sector:**

But when component/sector value is not given in percentage then component/sector values can be represented by using the below the angle of sector formula.

**Example problem:**

Below pie chart shows the percentage of the number of students enrolled in a school / in different activities.

To convert the pie chart into degrees we need to do the following conversions:

Total |
Percentage |
Degree |

Red cross | 10 | 36 |

NCC | 5 | 18 |

Human resource development club | 10 | 36 |

Debating club | 25 | 90 |

Eco club | 20 | 72 |

Scout | 30 | 108 |

**Formula to find the percentage of a sector when the angle of the sector is given**

**Example problem:**

Let us consider the Red Cross-sector from the above example

Percentage of Red Cross Sector=10

Total value is (Total Angle)=360 degrees

Therefore, the angle of the Red Cross sector=(10/100) ×360=36 degrees

**Formulas to find the angle of a sector when the percentage of the sector is given**

**Example problem:**

For this Red Cross-sector only let us consider the resultant angle 36 degrees and find percentage.

Here,

The angle of Red Cross sector=360 degrees

Total value is (Total percentage value)=100%

Percentage of Red Cross sector=(36/360) × 100=10%

**Data interpretation pie chart example question with the solution:**

Study the following pie chart given here which represents a domestic expenditure of family in percentage and answer the following questions. Total months income of the family is 55,750 rupees

**House rent per month is**

12/100 × 55,750

**The annual savings in the form of provident fund is**

(13/100) × (55750 ×12)

Annual PF savings=13% of (55750 ×12)

**The total amount per month, the family spends on food & entertainment combined together is**

(18%+9%) ×55750

⇒ 27/100 ×55750

Read More

Data Interpretation Basics | Data Interpretation Table |

Data Interpretation Bar Graph | Data Interpretation Line Graph |