enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Geometric standard deviation - Wikipedia

    en.wikipedia.org/wiki/Geometric_standard_deviation

    The geometric standard deviation is used as a measure of log-normal dispersion analogously to the geometric mean. [3] As the log-transform of a log-normal distribution results in a normal distribution, we see that the geometric standard deviation is the exponentiated value of the standard deviation of the log-transformed values, i.e. = ⁡ (⁡ (⁡)).

  3. Geometric distribution - Wikipedia

    en.wikipedia.org/wiki/Geometric_distribution

    The geometric distribution is the only memoryless discrete probability distribution. [4] It is the discrete version of the same property found in the exponential distribution . [ 1 ] : 228 The property asserts that the number of previously failed trials does not affect the number of future trials needed for a success.

  4. Log-normal distribution - Wikipedia

    en.wikipedia.org/wiki/Log-normal_distribution

    In probability theory, a log-normal (or lognormal) distribution is a continuous probability distribution of a random variable whose logarithm is normally distributed.Thus, if the random variable X is log-normally distributed, then Y = ln(X) has a normal distribution.

  5. Hypergeometric distribution - Wikipedia

    en.wikipedia.org/wiki/Hypergeometric_distribution

    In probability theory and statistics, the hypergeometric distribution is a discrete probability distribution that describes the probability of successes (random draws for which the object drawn has a specified feature) in draws, without replacement, from a finite population of size that contains exactly objects with that feature, wherein each draw is either a success or a failure.

  6. Geometric probability - Wikipedia

    en.wikipedia.org/wiki/Geometric_probability

    Problems of the following type, and their solution techniques, were first studied in the 18th century, and the general topic became known as geometric probability. ( Buffon's needle ) What is the chance that a needle dropped randomly onto a floor marked with equally spaced parallel lines will cross one of the lines?

  7. Particle-size distribution - Wikipedia

    en.wikipedia.org/wiki/Particle-size_distribution

    λ: Gas mean free path (cm) D 50: Mass-median-diameter (MMD). The log-normal distribution mass median diameter. The MMD is considered to be the average particle diameter by mass. σ g: Geometric standard deviation. This value is determined mathematically by the equation: σ g = D 84.13 /D 50 = D 50 /D 15.87

  8. Mean - Wikipedia

    en.wikipedia.org/wiki/Mean

    Comparison of the arithmetic mean, median, and mode of two skewed distributions Geometric visualization of the mode, median and mean of an arbitrary probability density function [5] In descriptive statistics , the mean may be confused with the median , mode or mid-range , as any of these may incorrectly be called an "average" (more formally, a ...

  9. Standard deviation - Wikipedia

    en.wikipedia.org/wiki/Standard_deviation

    The mean and the standard deviation of a set of data are descriptive statistics usually reported together. In a certain sense, the standard deviation is a "natural" measure of statistical dispersion if the center of the data is measured about the mean. This is because the standard deviation from the mean is smaller than from any other point.