3.1 Introduction to Probability and Technology Flashcards
Probability
Study of randomness, means the chance of an event occurring, basis of statistical inference
Randomness
chance behavior is unpredictable in the short run but has a regular and predictable pattern in the long run
Law of Large Numbers
as the number of repetitions of an experiment increase, the proportion with which a certain outcome is observed gets closer to the actual classical probability of that outcome, the relative frequency of an event is likely close to the classical probability
probability experiment
a repeatable process where the results are uncertain
outcome
result of a single trail of a probability experiment
sample space
set of all possible outcomes of a probability experiment. usually denoted by S.
Event
an outcome or set of outcomes of a probability experiment
Probability Model
a mathematical description of a random phenomenon. Has two parts: list of possible outcomes and a way of assigning probabilities to events
Axioms of Probability
A probability is a number that is assigned to each member of a collection of events from a random experiment that satisfies the following properties 1. P(S)=1 2. 0<P(E)<1 3. for each two events E1 and E2 with E1nE2=0 P(E1UE2)=P(E1)+P(E2)
Approaches to finding probabilities
the classical approach, the relative frequency approach, subjective probability, probability rules for more complicated situations
The Classical Approach
uses sample spaces to determine the numerical probability that an event will happen, no experiment, assumes that all outcomes in the sample space are likely to occur. # of outcomes in E/total # of outcomes in the sample space
Relative Frequency Approach
uses frequency distributions based on observations to estimate probability. Relies on an actual experiment. Frequency of E/Total number of trails in the experiment=f/n
Subjective Probability
the degree to which a given individual believes the event in question will happen
The Compliment
the set of outcomes in the sample space that are not included in that event
Mutually exclusive
have no outcomes in common, cannot occur at the same time