Uniform Distribution Probability Calculator

The uniform distribution is a probability distribution where all outcomes are equally likely. Use this calculator to find the probability between two values within a defined range, and also compute \(P(X \geq x)\) and \(P(X \leq x)\) for specific values.

P(x1 ≤ X ≤ x2):

P(X ≥ x1):

P(X ≤ x1):

P(X ≥ x2):

P(X ≤ x2):

Understanding the Uniform Distribution

The Uniform Distribution is a continuous probability distribution in which all outcomes between two limits are equally likely. It is often used to model scenarios where each outcome has the same chance of occurring within a specified range.

Key Components of the Uniform Distribution

  • Lower Limit (a): The minimum value in the range of outcomes.
  • Upper Limit (b): The maximum value in the range of outcomes.
  • x1: The lower bound of the interval of interest within the uniform distribution.
  • x2: The upper bound of the interval of interest within the uniform distribution.

Uniform Distribution Formula

The probability of a value falling between \( x_1 \) and \( x_2 \) in a uniform distribution is given by the formula:

\[ P(x_1 \leq X \leq x_2) = \frac{x_2 - x_1}{b - a} \]

Additionally, the cumulative distribution function (CDF) is used to calculate probabilities for \(P(X \geq x)\) and \(P(X \leq x)\):

  • P(X ≤ x): \( \frac{x - a}{b - a} \) for \( a \leq x \leq b \)
  • P(X ≥ x): \( \frac{b - x}{b - a} \) for \( a \leq x \leq b \)

Step-by-Step Example

Suppose we have a uniform distribution defined between \(a = 1\) and \(b = 10\), and we are interested in finding the probability that the value falls between \(x_1 = 2\) and \(x_2 = 5\). Additionally, we'll compute \(P(X \geq x_1)\), \(P(X \leq x_1)\), \(P(X \geq x_2)\), and \(P(X \leq x_2)\).

Step 1: Apply the Formula

Using the formula for \(P(x_1 \leq X \leq x_2)\):

\[ P(2 \leq X \leq 5) = \frac{5 - 2}{10 - 1} = \frac{3}{9} \approx 0.33333 \]

Therefore, the probability that a value will fall between 2 and 5 is approximately 0.33333, or 33.33%.

Step 2: Compute Additional Probabilities

Using the CDF formulas for \(P(X \geq x)\) and \(P(X \leq x)\):

  • P(X ≥ 2): \( \frac{10 - 2}{10 - 1} = \frac{8}{9} \approx 0.88889 \)
  • P(X ≤ 2): \( \frac{2 - 1}{10 - 1} = \frac{1}{9} \approx 0.11111 \)
  • P(X ≥ 5): \( \frac{10 - 5}{10 - 1} = \frac{5}{9} \approx 0.55556 \)
  • P(X ≤ 5): \( \frac{5 - 1}{10 - 1} = \frac{4}{9} \approx 0.44444 \)

Further Reading

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Suf is a senior advisor in data science with deep expertise in Natural Language Processing, Complex Networks, and Anomaly Detection. Formerly a postdoctoral research fellow, he applied advanced physics techniques to tackle real-world, data-heavy industry challenges. Before that, he was a particle physicist at the ATLAS Experiment of the Large Hadron Collider. Now, he’s focused on bringing more fun and curiosity to the world of science and research online.