⏳ Exponential Distribution Calculator

Calculate waiting-time probabilities for a continuous exponential distribution.

📊 Statistics📐 Formula included🧠 Practice questions✓ Free
Please enter valid values.

Formula and Explanation

Calculate waiting-time probabilities for a continuous exponential distribution.

ConceptFormula or rule
Exponential Distribution CalculatorF(x) = 1 − e⁻ˡᵃᵐᵇᵈᵃˣ · S(x)=e⁻ˡᵃᵐᵇᵈᵃˣ

How to Use This Calculator

  1. Enter the sample, counts, probabilities, or summary statistics requested above.
  2. Keep paired lists in the same order and separate values with commas.
  3. Select the correct test direction or sample/population option when available.
  4. Press Calculate and interpret the result together with the supporting statistics.

Worked Example

Example: With λ=0.2 per minute, the mean waiting time is 1/0.2=5 minutes.
✓ P(X≤5)=1−e⁻¹≈0.6321

Where This Is Used

School & coursework
Check homework, understand formulas, and verify step-by-step statistics exercises.
Research
Explore estimates, uncertainty, distributions, and relationships before using full statistical software.
Business & data analysis
Summarize variation, compare groups, and communicate data-driven findings clearly.

Common Mistakes to Avoid

⚠️
Confusing rate with mean
Mean waiting time equals 1/λ.
⚠️
Mixing time units
If λ is per hour, x must be in hours.
⚠️
Using it when hazard changes strongly over time
The exponential model assumes a constant rate.

Practice Questions

1. If λ=0.5, what is mean waiting time?
Answer: 2
2. What is survival at x=0?
Answer: 1
3. Can x be negative?
Answer: No.

Frequently Asked Questions

Is the exponential distribution memoryless?▾
Yes.
What is its mean?▾
1/λ.
What is its variance?▾
1/λ².

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