Log-Normal Distribution Probability Calculator

This calculator computes probabilities for the lognormal distribution using the mean (𝝁), standard deviation (𝝈), and a random variable value (π‘₯). It also visualizes the distribution and highlights the cumulative probability \( P(X \leq x) \).

P(X = ):

P(X < ):

P(X ≀ ):

P(X > ):

P(X β‰₯ ):

Understanding the Lognormal Distribution

The Lognormal Distribution is a continuous probability distribution of a random variable whose logarithm is normally distributed. It is widely used in fields like finance, reliability analysis, and biological modeling.

In particular, the Black-Scholes Model assumes that the price of financial assets follows a lognormal distribution, which allows it to model stock prices effectively over time.

Key Components of the Lognormal Distribution

  • Mean (𝝁): The mean of the underlying normal distribution.
  • Standard Deviation (𝝈): The standard deviation of the underlying normal distribution.
  • Random Variable (π‘₯): The value for which probabilities are being calculated.

Formula for Lognormal Distribution

The probability density function (PDF) for the lognormal distribution is:

\[ f(x|\mu, \sigma) = \frac{1}{x\sigma\sqrt{2\pi}} \exp\left(-\frac{(\ln(x) - \mu)^2}{2\sigma^2}\right) \]

Example Calculation

Let's assume the mean is \( \mu = 0 \), the standard deviation is \( \sigma = 1 \), and we want to find the probability for \( x = 1 \).

Further Reading

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Senior Advisor, Data Science | [email protected] | + posts

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.