probability meaning

• Noun: probability  `próbu'bilitee
  1. A measure of how likely it is that some event will occur; a number expressing the ratio of favourable cases to the whole number of cases possible
     "the probability that an unbiased coin will fall with the head up is 0.5"
     - chance 
  2. The quality of being probable; a probable event or the most probable event
     "for a while mutiny seemed a probability"; "going by past experience there was a high probability that the visitors were lost"

  Derived forms: probabilities

  See also: probabilistic, probable

  Type of: amount, measure, quality, quantity

  Antonym: improbability

  Encyclopedia: Probability

• 
  [Economics]
  The likelihood that an event or a particular result will occur. It can be represented on a scale by a number between 0 (zero probability of the event happening, i.e. it is certain not to) and 1 (certainty that it will occur). It is treated mathematically on this basis in statistics.
• 
  [Electronics]
  1. The branch of mathematics concerned with the likelihood of an event’s occurrence. It has many applications in quality control and physics.
  2. The mathematical likelihood that an event will occur.
  
• 
  [Finance]
  The relative likelihood of a particular outcome among all possible outcomes.

[Medicine]
The study of chance processes or the relative frequency characterizing a chance process.

• a priori probability:    [Finance]Probabili ...
• conditional probability:    Noun: conditional ...
• contingent probability:    Noun: contingent p ...

Examples

1. what is the probability that it is a prime?
2. a higher probability means more confidence.
3. a probability of 1 represents certainty.
4. this is often quoted above of 67% probability.
5. in all probability he is already left.