Chapter 3 Flashcards
Why study probability?
Gives us a way to evaluate risks associated with just about any sort of behavior
What is probability?
Key to accessing and understanding risks involved in any decision-making process
How do social scientists use probability?
Assess the likelihood of making incorrect inferences when generalizing about human behavior
What is probability in simple terms?
Likelihood of an event expressed in numerical terms as a fraction, decimal, or percent
What does a probability of zero indicate?
The event will never happen
What does a probability of one indicate?
It will absolutely happen
What values can’t be a probability?
A negative number
What is a probability experiment?
A situation involving chance or probability that leads to observable and measurable results
How many trials could a probability experiment consist of?
One or many trials
How many outcomes come from each trial?
Only one outcome for each trial
What do all probability experiments have in common?
Must have more than one possible outcome, can be specified in advance, due to chance
What is a non-example of probability?
Only has one possible outcome, can’t be specified in advanced, and outcomes are not due to chance
What are examples of non-probability?
Football player running for a touchdown, buying a raffle ticket, your church sponsoring a Vegas night to raise money for charity
What is a trial?
Single performance of a probability event
What is an outcome?
The result of a single probability experiment
What is a set?
Describe collections of objects or values that have been defined according to a rule or statement
What is each object or value in a set?
An element of the set
What are sets denoted by?
A capital letter
What is an event?
Subset of the sample space, collection of all possible outcomes of a probability experiment
What does a simple event consist of?
Single outcome
What does a compound event consist of?
More than one outcome
What is the sample space?
Description of all possible outcomes of a probability experiment
What is the first step in determining the probability of any single outcome?
Writing out the description of the sample space
What does the sum of all probabilities of all possible outcomes in the sample space must equal to?
One
What is the formula for any given outcome?
P(x) = X / Total outcomes in the sample space
What is the complement of an event?
All outcomes that are not the event
What happens if the complement of an event is not occurring?
Designated as a prime
What can the relationship for complement of events be shown as?
P(A’) = 1- P(A)
How can you find the probability associated with a prime number?
Take 1 and subtract that from the sample space value then that is the value of the prime complement value
What are the three ways to arrive at a probability statement?
Theoretical probability, empirical probability, and subjective probability
What is theoretical or classical probability?
Assumption about the nature of the event, assumed that n events are equally likely to occur
What is empirical or relative frequency probability?
Based on the observed outcomes of one or a series of trials
What type of probability is used most often in statistical inference procedures?
Empirical
What is subjective probability?
Based on personal belief about the likelihood of an event occurring