Biology 2244A/B Lecture Notes - Lecture 4: Sample Space
Document Summary
Under assumption, probability of observed event (p-value) is small, conclude assumption is not correct. Simple event outcome that cannot be broken down. Notation: p probability, a,b,c an event, p(a,b,c) probability of event. Number of ways event can occur/number of different simple events (sample space) Subjective probability use knowledge to make probability. Law of large numbers - lots of repetitions = closer to actual probability. Complement of event a is a-bar; is the events that don"t occur: 1-a = a-bar. Compound event combining events: p(a or b) probability of a or b occurring. Formal addition rule p(a or b) = p(a) + p(b) p(a and b: disjoint (mutually exclusive) events cannot occur at same time. If true, p(a or b) = p(a) + p(b: complement events p(a or a-bar) = p(a) + p(a-bar) = 1. P(a and b) probability of a occurring followed by b occurring: multiply probabilities together (p(a) with p(b))