I do not add probabilities to anybody!
Empirical probabilities.
Sum of all probabilities is 1.
Statistical Probabilities was created on 1997-11-22.
A Punnett square is used to lay out the possible genotypes of offspring based on the genotypes of the parents being bred. From this, the probabilities of certain phenotypes and genotypes can be determined.
The sum of the probabilities of all possible outcomes is 1.
Things and numbers don't have probabilities. Situations and events that can happen have probabilities.
The fact that probabilities are proportions means that they are less than or equal to 1.
Probabilities are calculated or estimated in a variety of methods. A non-quantitative means, used by weather forecasters, is to look at general conditions, is provide probabilies based on all indicators. In this way, the probabilities reflect their belief of certain events occurring from 0 (will not occur) to 100% (certain to occur). A second wasy probabilities are determined is to collect data, and determine the relative frequency of a particular event. Perhaps 10% of all motorists drive above the speed limit in a particular area, based on data collection, so we can state the probability of a motorist speeding in a certain area is 10%. Finally, probabilities are developed based on other known probabilites or assuming equally likely outcomes. If I have 5 outcomes, and they are equally likely, then the probability of each one occurring in 20% if these outcomes are independent and mutually exclusive. If I know the chance of coin flip coming up heads is 0.50, I can determine the probability of two coins coming up heads is 0.5 x 0.5 = 0.25.
If the events are independent then you can multiply the individual probabilities. But if they are not, you have to use conditional probabilities.
Michel Simonnet has written: 'Measures and probabilities' -- subject(s): Probabilities, Measure theory
Conditional probabilities arise when you revise the probabilities previously attached to some events in order to take new information into account. The revised probabilities are 'conditional on the new information you have received'.