What is a common probability?
common probability (P) concerns the probability of two events that occur simultaneously, where you can understand the event as anything, such as a drawn card or dice role. Usually, the term joint two simultaneous occurrences, but sometimes it can be applied to more than two events. There are specific rules in statistics and probability that follows how to assess this probability. The simplest methods are used by special multiplication rules. In addition, Independent events or use Replacing require consideration and change of calculations.
The simplest form of joint probability occurs when two independent events are considered. This means that the result of each event does not depend on others. For example, when rolling two cubes, an individual might want to know the common probability that he would get two sixs in one cylinder. Each event is independent and gaining six in one accident of what happens to another. It can be the oneto express as P (A × b). There is a 1/6 chance of hesitation six to six -sided matrix. P (A and B) is therefore 1/6 × 1/6 or 1/36.
When the probability of the joint is evaluated on a dependent event, the multiplication rule changes. Although such events are "common", one affects the outcome of the others. These changes should be considered when calculating.
Consider the possibility of drawing two red cards from normal deck 52 cards. Since half of the cards are red, the likelihood of eliminating one red card or P (A) 1/2. Although the cards are drawn at the same time, the second event has a different level of probability, because there are now 51 cards and 25 red. P (B), drawing the second red card, is really P (b | a), which sounds like B given A. This is 25/51, instead of 1/2.
The formal rule of multiplication for dependent events is p (a) × p (b | a). In this example there is a common truthEatness of two red cards 1/2 × 25/51. It equals 25/102 or, as more common, can be written as a decimal place with three places: 0.245.
In determining the correct use of the multiplication to be used, it is important to consider the replacement concept. If the first red card was drawn and a new red card was placed before drawing the second card, these two events will become independent. A common probability with alternative laws such as a simple independent probability, and is evaluated as P (a) × P (b).