210 likes | 371 Vues
Addition Rules of Probability……. OBJECTIVE. Recognize Mutually Exclusive Events Use the Addition Rule of Probability. RELEVANCE. To find the likelihood of an event occurring by observing the long-term proportion in which a certain outcome is observed. Card Facts……. 52 cards in the deck
E N D
OBJECTIVE • Recognize Mutually Exclusive Events • Use the Addition Rule of Probability
RELEVANCE To find the likelihood of an event occurring by observing the long-term proportion in which a certain outcome is observed.
Card Facts…… • 52 cards in the deck • 4 suits • 13 cards in each suit (diamond, hearts, clubs, spades) • Face cards – jack, queen, king • 26 red cards; 26 black cards
Mutually Exclusive Events…… • Events that cannot occur at the same time. • For example: Being a junior and being a senior are mutually exclusive.
Getting a 4 and a 6 Getting an odd # and an even # Getting an odd# and a # less than 4 Getting a # greater than 4 and a # less than 4 Getting a 3 and an odd # Mutually Exclusive Mutually Exclusive Not M.E. Mutually Exclusive Not M.E. Determine which events are mutually exclusive when a single die is rolled…..
Getting a 7 and J Getting a club and king Getting a face card and an ace Getting a face card and a spade M.E Not M.E. M.E. Not M.E. You Try…Which are mutually exclusive when a single card is drawn from a deck?......
Addition Rule – M.E. Events…… • When 2 events are mutually exclusive, the probability that A or B will occur is
Example…… • A box contains 3 glazed, 4 jelly, and 5 chocolate doughnuts. If a person selects one doughnut at random, find the probability that it is either glazed or chocolate.
Answer…… • Sample Space = 3+4+5 = 12 doughnuts • P(glazed or choc) = P(glazed) + P(chocolate)
Example…… • At a political rally, there are 20 republicans, 13 democrats, and 6 independents. If a person is selected at random, find the probability that he or she is either a democrat or an independent.
Answer…… • Sample Space = 20+13+6=39 • P(dem orind) = P(dem)+P(ind)
Example…… • A day of the week is selected at random. Find the probability that it is a day of the weekend.
Answer…… • Sample Space = 7 days in a week P(Sat or Sun)= P(Sat) + P(Sun)
Addition Rule – NOT Mutually Exclusive…… • When 2 events are NOT mutually exclusive, the probability that A or B will occur is • The Formal Addition Rule
Example…… • A single card is drawn from a deck. Find the probability that it is a king or club.
Example…… • In a hospital unit there are 8 nurses and 5 doctors. 7 nurses and 3 doctors are female. If a staff person is selected, find the probability that the subject is a nurse or a male. • Suggestion: Make a contingency table.
Find the P(nurse or male) • Let n = nurse and m = male • P(n or m) = P(nurse) + P(m) – P(nurse and male)
Example…… • On New Year’s Eve, the probability of a person driving while intoxicated is 0.32, the prob. of a person having an accident is .09, and the prob. of a person having an accident while intoxicated is .06. What is the probability of a person driving while intoxicated or having an accident?
Answer…… • P(intox or acc) = P(intox) + P(acc) – P(intox and acc)