STATS 250 Lecture Notes - Lecture 3: Conditional Probability
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STATS 250 Full Course Notes
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Stats 250: introduction to statistics - lecture 3: probability. P(a) = the degree to which a given individual believes that the event a will happen. P(a) = proportion of times a" occurs if the random experiment (circumstance) is repeated many, many times. P(a) = proportion of balls in the basket that have an a" on them. There are 10 balls in a basket: 3 are blue and 7 are white. Probability is not a statement about individuals but rather a statement about populations. The probability of any outcome is always between 0 and 1. The probability of an event not being satisfied is the complement of the event. Two events, a and b, are mutually exclusive (or disjoint) if they do not contain any of the same outcomes. If a and b are disjoint, then p(a and b) = 0. If a and b are disjoint, then p(a or b) = p(a) + p(b)
