Exam 2 Flashcards
probability
quantifies long-term randomness
law of large numbers
as n increases, proportion of occurrences of a given outcoe approaches a particular number
relative frequency
large number of trials to find long run proportion of outcomes
probability experiment
chance process leading to well-defined outcomes
outcome
result of a trial of a probability experiment
sample space
set of all possible outcomes
event
subset of a sample space
corresponds to a particular outcome or group of outcomes
3 basic interpretations of probability
classical
empirical (relative frequency)
subjective
complement
set of all outcomes not included in event
intersection of 2 events
outcomes in 2 different events
union of 2 events
outcome in one event or the other
disjoint events
do not have any common outcomes
mutually exclusive
conditional probability
reduction of sample space by imposing a condition
2 ways to check if two events are independent
if either are true, they are independent
fundamental counting rule
in a sequence of n events in whcih the first has k1 possibilities, the second has k2 and so on, the total number of possibilities of the sequence will be
k1k2k3…kn
sensitivity
p(POS|S)
positive test given state present
specificity
p(NEG|S^c)
negative test given state not present
permutation
arrangement of objects in a specific order
combination
grouping of objects where order does not matter