Unit 1: Probability Flashcards
what is probability?
chance/likelihood of an event happening
types of probability
subjective: probability based on intuition
experimental: observed probability based on trials
theoretical: based on all possible outcomes given that all outcomes are equally likely
what is a set?
a collection of distinct objects denoted using set notation {…}
n(set name) = #
what is a null set?
a set with no elements, the null set is a subset of every set, denoted by {}
what is a subset?
a set whose members are all members of another set
any set has 2^n subsets where n is the number of elements in the original set
what is a sample space?
set of all possible outcomes, denoted by S = {…}
what is an event?
set of all outcomes that have a common characteristic, denoted by A
what is a complement?
a set of all outcomes that are NOT included in an event, denoted by A’ or ~A
what does odds in favour mean?
the ratio of the probability that an event will occur to the probability that an event will not occur
what does odds against mean?
the ratio of the probability that an event will not occur to probability that will occur
what is intersection of sets and its symbol?
(∩): contains all elements that are common to all sets
the middle of the venn diagram
what is union of sets and its symbol?
(∪): contains distinct elements that belong to the collection of ALL sets
the entire venn diagram
what are disjoint sets?
sets that have no common elements BETWEEN sets
2 non-overlapping circles
what is the principle of inclusion and exclusion?
the sum of each set minus the intersection of A and B
what does mutually exclusive mean?
disjoint events that have different attributes and can’t occur at the same time
what does non-mutually exclusive mean?
events that have common characteristics which means they CAN occur simultaneously
what is an independent event?
when the occurrence of one event has no effect on the occurrence of another, the events are independent
what is a dependent event?
when the probability of one event influences the probability of another event
what is conditional probability?
P(B|A), the probability that B occurs, given A has already occurred
the sample space for the second event is reduced by the first event
