Probability Calculator
Calculate probability for single events, unions, intersections, and conditional probability. Supports all basic probability operations.
How to Use the Probability Calculator
- Enter your data set or statistical values in the input fields.
- Click Calculate to process the data.
- Review the computed result with detailed breakdown.
- Modify inputs or add more data points for further analysis.
Quick Reference
| From | To |
|---|---|
| Mean [2,4,6] | 4 |
| Median [1,3,5,7] | 4 |
| Mode [2,2,3,5] | 2 |
| σ [2,4,4,4,5,5,7,9] | 2 |
| z-score (x=85, μ=70, σ=10) | 1.5 |
| P(A)+P(B)−P(A∩B) | P(A∪B) |
Use Cases
- •Analyzing data sets for research papers or school projects.
- •Checking statistical calculations before including them in reports.
- •Understanding data distributions and variability in experiments.
- •Making data-driven decisions in business or academic contexts.
Formula
Single: P = favorable/total. Union: P(A∪B) = P(A) + P(B) − P(A∩B). Intersection: P(A∩B) = P(A) × P(B). Conditional: P(A|B) = P(A∩B) / P(B).
Frequently Asked Questions
What is probability?
Probability measures the likelihood of an event occurring, expressed as a number between 0 (impossible) and 1 (certain).
What is the union of two events?
The union P(A∪B) is the probability that event A or event B (or both) occurs. P(A∪B) = P(A) + P(B) − P(A∩B).
What is conditional probability?
Conditional probability P(A|B) is the probability of A occurring given that B has already occurred. P(A|B) = P(A∩B) / P(B).
When can I multiply probabilities?
You can multiply P(A) × P(B) to get P(A∩B) only when events A and B are independent — meaning one does not affect the other.