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  2. Expected value - Wikipedia

    en.wikipedia.org/wiki/Expected_value

    v. t. e. In probability theory, the expected value (also called expectation, expectancy, expectation operator, mathematical expectation, mean, expectation value, or first moment) is a generalization of the weighted average. Informally, the expected value is the mean of the possible values a random variable can take, weighted by the probability ...

  3. Expectation–maximization algorithm - Wikipedia

    en.wikipedia.org/wiki/Expectation–maximization...

    t. e. In statistics, an expectation–maximization (EM) algorithm is an iterative method to find (local) maximum likelihood or maximum a posteriori (MAP) estimates of parameters in statistical models, where the model depends on unobserved latent variables. [1] The EM iteration alternates between performing an expectation (E) step, which creates ...

  4. Maximum likelihood estimation - Wikipedia

    en.wikipedia.org/wiki/Maximum_likelihood_estimation

    Maximum likelihood estimation. In statistics, maximum likelihood estimation (MLE) is a method of estimating the parameters of an assumed probability distribution, given some observed data. This is achieved by maximizing a likelihood function so that, under the assumed statistical model, the observed data is most probable.

  5. Survival analysis - Wikipedia

    en.wikipedia.org/wiki/Survival_analysis

    Survival analysis is a branch of statistics for analyzing the expected duration of time until one event occurs, such as death in biological organisms and failure in mechanical systems. This topic is called reliability theory, reliability analysis or reliability engineering in engineering, duration analysis or duration modelling in economics ...

  6. PERT distribution - Wikipedia

    en.wikipedia.org/wiki/PERT_distribution

    PERT distribution. In probability and statistics, the PERT distributions are a family of continuous probability distributions defined by the minimum (a), most likely (b) and maximum (c) values that a variable can take. It is a transformation of the four-parameter beta distribution with an additional assumption that its expected value is.

  7. Random walk - Wikipedia

    en.wikipedia.org/wiki/Random_walk

    If v s is the starting value of the random walk, the expected value after n steps will be v s + nμ. For the special case where μ is equal to zero, after n steps, the translation distance's probability distribution is given by N (0, n σ 2 ), where N () is the notation for the normal distribution, n is the number of steps, and σ is from the ...

  8. Prediction interval - Wikipedia

    en.wikipedia.org/wiki/Prediction_interval

    Prediction interval. In statistical inference, specifically predictive inference, a prediction interval is an estimate of an interval in which a future observation will fall, with a certain probability, given what has already been observed. Prediction intervals are often used in regression analysis. A simple example is given by a six-sided die ...

  9. G-test - Wikipedia

    en.wikipedia.org/wiki/G-test

    We can derive the value of the G-test from the log-likelihood ratio test where the underlying model is a multinomial model.. Suppose we had a sample = (, …,) where each is the number of times that an object of type was observed.