Pie diagram
Also called: Pie chart · Topic: Economic Data: Census, NSS, Surveys and Statistical Tools · NCERT: Class 11, Ch 4 "Presentation of Data"; Class 11, Ch 8 "Use of Statistical Tools"
Meaning
A pie diagram is a circle divided into sectors (slices). Each slice shows one part's share of a total. The whole circle, 360°, stands for 100%, so: 1% = 360° ÷ 100 = 3.6° To draw a slice, multiply its percentage by 3.6 to get its angle. A pie diagram suits data that add up to a whole, such as the parts of a budget or of a population.
Example
In Census 2011, main workers were 29.8% of India's population, which gives a slice of about 107°. Marginal workers were 9.9%, about 36°. Non-workers were 60.3%, about 217°. Together the slices make the full 360°.
Don't confuse with
- Component bar diagram: this shows the parts of a total as pieces of one bar, not as slices of a circle. It is easier for comparing several totals side by side.
Related concepts
- Raw data
- Classification
- Chronological classification
- Spatial classification
- Qualitative classification
- Quantitative classification
- Attribute
- Continuous variable
- Discrete variable
- Frequency