Probability
Definitions
Probability - Probability is the branch of mathematics which studies the possible outcomes of given events together with their relative likelihoods and distributions. In common usage, the word "probability" is used to mean the chance that a particular event (or set of events) will occur expressed on a linear scale from 0 (impossibility) to 1 (certainty), also expressed as a percentage between 0 and 100%.
• Population - generalization from experience which is indefinitely large (e.g., the total number of throws that might conceivably by made in unlimited time with a particular pair of dice). Any actual set of throws can then be regarded as a sample drawn from this p•
•Theoretical Probability – When the circumstances of an experiment are always identical we can arrive at a value for the probability of a particular event by using mathematical reasoning, often based on an argument reflecting some form of symmetry.
• Conditional Probability – works in the same way that simple probability does, the only difference is that we are provided with some prior knowledge of extra conditions about the outcome of the data.
Equations
Relative frequency = n(A)/N
Theoretical Probability of event A = n(A)/n(U)
Conditional Probability of event A given event B = p(A|B) = p(A∩B)/p(B), p(B) ≠ 0
Intersection = p(A∩B)
Union = p(AU B)
Sample Venn Diagrams
