(statistics) The half-range of an interval about a central point for the distribution, such that half of the values from the distribution will lie within the interval and half outside.

(mathematics) The mathematical study of probability (the likelihood of occurrence of random events in order to predict the behavior of defined systems).

(statistics) A distribution of all possible values of a random variable together with an indication of their probabilities.

(mathematics) A measurable space having a unit measure

(mathematics) the probability that a certain outcome will occur, as determined through reasoning or calculation.

(mathematics) The probability that a certain outcome will occur, as determined through experiment.

(probability theory) probability density function

Graph paper with vertical and horizontal rules, the latter spaced evenly and the former according to a scale that allows a plotted probability curve — usually that of a normal distribution — to appear linear.

(law) A legal standard, applied in many jurisdictions for deciding the outcome of civil disputes, which requires that a dispute be decided in favor of the party whose claims are more likely to be true.

(statistics) The probability of an event obtained without the knowledge of occurrence of other events that bear on it.