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Displaying Data
Bar charts and pie charts turn a frequency table into a picture that is quick to read.
Pictures of Data
A bar chart uses the height of each bar to show a frequency, making categories easy to compare at a glance.
Favourite sport in a class survey
Football
12
Basketball
8
Swimming
5
Tennis
3
Change a value and watch: The height of each bar shows its frequency. Football is the most popular, with the tallest bar.
Pie Charts
A pie chart shows each category as a slice of a full circle (°). The angle of each slice is proportional to its frequency:
angle = (category frequency ÷ total frequency) × °
Example 1 — finding a pie chart angle
people were surveyed, and of them chose category A. Find the angle of category A's slice in a pie chart.
- Find the fraction of the total:
- Multiply by °: °
Answer: °
Practice
people were surveyed, and chose a certain category. Find the angle of that category's pie chart slice.
Your answer
More lessons in Descriptive Statistics and Basic Probability · Next: Comparing Data Sets · Previous: Range and Quartiles