STAT1008 Study Guide - Final Guide: Normal Distribution, Confidence Interval, Prediction Interval
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Additive: p(a or b) = p(a)+p(b)-p(a and b). Multiplicative: p(a and b) = p(a) p(b if a). Conditional: p(b if a) = p(a and b)/p(a). ( event b happens if a happens) Special cases: if a and b are disjoint (can"t occur on same trial): p(a or b)=p(a)+p(b). If a and b are independent (a occurring doesn"t change probabilities of b): p(a and. Tree diagrams-the initial set of branches show the probabilities from one set of events and the second set of branches show conditional probabilities (with the initial branch as the condition). Multiplying along any set of branches uses the multiplicative rule to find the joint probability for that pair of events. 11. 3 a random variable denotes a numeric quantity that changes from trial to trial in a random process. We say a random variable is discrete if it has a finite set of possible values. A variable that can take any value within some interval is called continuous.
