Chapter 5: Probability Flashcards
experiment
a procedure carried out under controlled conditions
outcome
result of an experiment
sample space (S)
all possible outcomes of an experiment
n(S)
size of sample space
event (E)
outcome(s) that we want
n(E)
size of event
P(E)
probability of “event E”
equally likely outcomes (ELO)
each outcome has an equal probability of occuring
probability
likelihood of an event happening
intersection (∩)
“and”
union (∪)
“or”
complement (A’)
event A not occuring
additive rule
P( A or B) = P(A) + P(B) - P(A and B)
mutually exclusive (disjoint)
events A and B can never happen together
independent events
event A does not influence event B
multiplication rule for independent events
P(A and B) = P(A) * P(B)
conditional probability ( P(B|A) )
probability of an event given that another event happened/is known to happen
conditional probability rule
P(B|A) = P(A and B)/P(A)
general multiplicative rule
P(A and B) = P(A)*P(B|A)
tree diagram
diagram that helps visualize probabilities with multiple events
permutations
arrangement of elements or some of the elements of a set such that order matters
combinations
arragement of elements such that order does not matter
fundamental counting principle
multiply the number of ways you can complete each stage
