When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Expected mean squares - Wikipedia

    en.wikipedia.org/wiki/Expected_mean_squares

    Definition [ edit ] When the total corrected sum of squares in an ANOVA is partitioned into several components, each attributed to the effect of a particular predictor variable, each of the sums of squares in that partition is a random variable that has an expected value .

  3. Expected value - Wikipedia

    en.wikipedia.org/wiki/Expected_value

    The book extended the concept of expectation by adding rules for how to calculate expectations in more complicated situations than the original problem (e.g., for three or more players), and can be seen as the first successful attempt at laying down the foundations of the theory of probability. In the foreword to his treatise, Huygens wrote:

  4. Variance - Wikipedia

    en.wikipedia.org/wiki/Variance

    A square with sides equal to the difference of each value from the mean is formed for each value. Arranging the squares into a rectangle with one side equal to the number of values, n , results in the other side being the distribution's variance, σ 2 .

  5. Conditional expectation - Wikipedia

    en.wikipedia.org/wiki/Conditional_expectation

    The unconditional expectation of rainfall for an unspecified day is the average of the rainfall amounts for those 3652 days. The conditional expectation of rainfall for an otherwise unspecified day known to be (conditional on being) in the month of March, is the average of daily rainfall over all 310 days of the ten–year period that fall in ...

  6. Chi-squared distribution - Wikipedia

    en.wikipedia.org/wiki/Chi-squared_distribution

    Because the square of a standard normal distribution is the chi-squared distribution with one degree of freedom, the probability of a result such as 1 heads in 10 trials can be approximated either by using the normal distribution directly, or the chi-squared distribution for the normalised, squared difference between observed and expected value.

  7. Martingale (probability theory) - Wikipedia

    en.wikipedia.org/wiki/Martingale_(probability...

    Similarly, if a submartingale and a martingale have equivalent expectations for a given time, the history of the submartingale tends to be bounded above by the history of the martingale. Roughly speaking, the prefix "sub-" is consistent because the current observation X n is less than (or equal to) the conditional expectation E[X n +1 | X 1 ...

  8. Expectation value (quantum mechanics) - Wikipedia

    en.wikipedia.org/wiki/Expectation_value_(quantum...

    In quantum mechanics, the expectation value is the probabilistic expected value of the result (measurement) of an experiment. It can be thought of as an average of all the possible outcomes of a measurement as weighted by their likelihood, and as such it is not the most probable value of a measurement; indeed the expectation value may have zero probability of occurring (e.g. measurements which ...

  9. 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.