Probability Scale
Values from 0 (impossible) to 1 (certain).
Key idea
Values from 0 (impossible) to 1 (certain).
In depth
The scale runs from 0 (impossible) to 1 (certain), often expressed as fractions, decimals or percentages. 0.5 means even chance. It lets you compare uncertain events on one line.
Worked example
A 0.05 probability of rain is 5%, unlikely but possible.
Real-world uses
- Describing risk in everyday language, from impossible to certain, in weather and sport reports
Common mistake
Using values outside the range 0–1.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Probability Scale?
Values from 0 (impossible) to 1 (certain). It is a topic at the beginner level in Probability & Statistics.
Where is Probability Scale used in real life?
Real-world examples: Describing risk in everyday language, from impossible to certain, in weather and sport reports.
What should I learn before Probability Scale?
Make sure you are comfortable with Basic Probability, the previous topic in Probability & Statistics.
What is a common mistake with Probability Scale?
Using values outside the range 0–1.
How can I practise Probability Scale?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Probability Scale?
Move on to Complementary Events next.
Related beginner topics in Probability & Statistics
- Types of Data – Categorical vs numerical, discrete vs continuous.
- Frequency Tables – Count how often each value occurs.
- Tally Charts and Pictographs – Simple visual summaries of counts.
- Bar Graphs – Compare categories using bars.
- Pie Charts – Show parts of a whole as sectors.
- Line Graphs – Show change over time.