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Sample Space
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The collection of all possible outcome values. The same space has a probability of 1.
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Disjoint events
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Two events are disjoing or mutually exclusive if they have no outcomes in common.
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Addition Rule
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If A and B are disjoint, then the probability of A or B is P(a)+ P(B)
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General Addition Rule
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For any two events, A and B, the probability of A or B is P(A)+P(B)-P(A and B)
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Conditional Probability
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P(A and B)/ P(B)
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Independence
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Two events are independent if knowing whether one event occurs does not alter the probability that the other event occurs
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Multiplication Rule
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If A and B are independent events, then the probability of A and B is P(A and B)= P(A) x P(B)
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General Multiplication Rule
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For any two events, A and B, the probability of A and B is P(A and B)= P(A) x P(AlB)
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Tree diagram
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A display of conditional events or probabilities that is helpful in thinking through conditioning
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Random phenomenon
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A phenomenon is random if we know what outcomes could happen, but not which particular values will happen
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Probability
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The probability of an event is a number between 0 and 1 that reports the liklihood of the event's occurrence. A probability can be derived from equally likely outcomes, from the long-run relative frequency of the event's occurrence, or from known probabilities. We wrie P(A) for the probability of the event A.
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Trial
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A single attempt or realization of a random phenomenon
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Outcome
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The outcome of a trial is the value measured, observed, or reported for an individual instance of that trial
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Event
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A collection of outcomes. Usually we identify events so that we can attach probabilities to them. We denote events with bold capital letters such as A, B , or C
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Law of Large Numbers
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States that the long-run relative frequency of repeated independent events settles down to the true relative frequency as the number of trials increases
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