How it works
Independent joints multiply; unions use inclusion-exclusion. Normal areas use standardized z-scores and Φ.
P∩=P(A)P(B) · P∪=P(A)+P(B)−P∩ · Φ((x−μ)/σ)
When to use
Use this tool when you need to: try two events at 0.5, XOR with 0.65 & 0.349, or normal μ=68 σ=4 from 60 to 72 (~81.9%).
How to use this tool
- Enter your values in the fields above.
- Review the formula and any mode options for your problem.
- Read the result and the step-by-step solution.
Try two events at 0.5, XOR with 0.65 & 0.349, or normal μ=68 σ=4 from 60 to 72 (~81.9%).
Frequently asked questions
- What is the Probability Calculator?
- Independent joints multiply; unions use inclusion-exclusion. Normal areas use standardized z-scores and Φ.
- How do I use the Probability Calculator?
- Enter the required values, then calculate. The Probability Calculator shows results, formulas, and step-by-step work when available. No account is required.
- What formula does the Probability Calculator use?
- P∩=P(A)P(B) · P∪=P(A)+P(B)−P∩ · Φ((x−μ)/σ)
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