# Stats Exam 2

 .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } AND= OR= Multiply, independent events?Add, mutually exclusive? Fundamental Counting Rule In a sequence of events (like choosing what piece of clothes to wear), multiply the numbers together to get the total number of combinations possible. Permutations Key words When order matters! "arrange, order, rearrange, rank, sequence, in how many ways can things be ordered" Permutation formulas number of permutations of n objects: n! (arrange) nPr= n!÷(n-r)! (selected piece and arrange them)n= # of objects (bigger #)r= selected # (smaller #) Combinations Key Words Order doesn't matter!"choose, select, team, committee" Combinations formula nCr= n!÷(n-r)!r!n= # of objects (bigger #)r= selected # (smaller #) Pascals's triangle 11 11 2 11 3 3 11 4 6 4 11 5 10 10 5 1 Probability of 0 Probability of 1 0= event never occurs1= event always occurs Drawing a sample space -tossing a coin -tossing 2 coins -rolling a die -heads tails-HH TT HT TH-1 2 3 4 5 6 Classical probability formula Prob.= (# of successful outcomes)÷(# of total outcomes) The Compliment opposite of event 1-fraction probability= compliment Mutually Exclusive 2 events that can't occur at the same time, only use the word OR with this condition When things are not mutually exclusive add two conditions and subtract overlap Example: P(king) + P(club) - P(king of clubs)4/52 + 13/52 - 1/52 Independent Events if event A doesn't affects the probability of event B P(A AND B)= P(A) • P(B) When events are not independent Don't forget to reduce the denominator by one for each next fraction because you wouldn't be returning "the marbles to the bag" When doing a tough word problem REWRITE THE QUESTION. Find out what you need and write out what you're finding the probability for. Example: P(1st yes AND 2nd yes AND 3rd yes) Conditional Probability conditional statement using the words "if" or "given that" Conditional Probability formula P(B given A)= P(A and B) ÷ P(A) .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } Authortenorsextets ID76299 Card SetStats Exam 2 Descriptionread title Updated2011-03-30T23:55:19Z Show Answers