PSYB07H3 Lecture Notes - Lecture 4: Conditional Probability, Mutual Exclusivity, Odds Ratio
Document Summary
Empirical view: toss a (cid:272)oi(cid:374) re(cid:272)ord the out(cid:272)o(cid:373)es, 10 times: 7 heads 0. 7, 20 times: 12 heads 0. 6, 100 times: 55 heads 0. 5, 1000 times: 520 heads 0. 52, p(head) = 0. 5. Analytical view: two possible outcomes head, tail, event outcome head, p(head) = 1/2 = 0. 5. Probability of rolling a (cid:862)(cid:1005)(cid:863) or (cid:862)(cid:1006)(cid:863) or (cid:862)(cid:1007)(cid:863) or (cid:862)(cid:1008)(cid:863) or (cid:862)(cid:1009)(cid:863) or (cid:862)(cid:1010)(cid:863) p(1 or 2 or 3 or 4 or 5 or 6) = p(1) + p(2) + p(3) + p(4) + p(5) + p(6) Pro(cid:271)a(cid:271)ility of rolli(cid:374)g a (cid:862)(cid:1096)4(cid:863) or (cid:862)a(cid:374) odd (cid:374)u(cid:373)(cid:271)er(cid:863) p(cid:894)(cid:1096)4 or odd(cid:895) = 1: (cid:862)(cid:1096)4(cid:863) or (cid:862)odd(cid:863, (cid:862)(cid:1096)4(cid:863) {4, 5, 6, (cid:862)odd(cid:863) {1, 3, 5, 5 & 5 over lap, overlapping not mutually exclusive. Mutually exclusive: occurrence of one event preclude the occurrence of the other. Independent event: two events are independent if the occurrence of one event does not influence the likelihood of the other event (two events are occurring)
