STAT 20 Lecture Notes - Lecture 8: Mutual Exclusivity, Fair Coin

• School: Berkeley
• Department: Statistics
• Course: STAT 20
• Professor: Fletcher Ibser

Document Summary

P(a or b) = p(a) + p(b) - p(a and b) P(a or b)= p(a) + p(b) - p(a and b) Two events are mutually exclusive if they can"t both happen. If a and b are mutually exclusive , p(a or b)= p(a) + p(b) Book says: if you want to find chance that event a happens or event b happens, check to make sure they are mutually exclusive. =p(at least one 6 in two die rolls) P(at least one 6 in 5 die rolls. Chapter 15 binomial formula ex) suppose alice, betty, and charles will sit in three chairs. Three ways someone can sit first, then there are two ways the others can sit, then there is one last way someone can sit. New ex) if alice betty are female, charles is m then ffm, fmf, mff. Ex: find chance of exactly 2 heads in 3 fair coin tosses. P(2h in 3 tosses)= p(hht or hth or thh)