Inteoduction To Probability Flashcards
How is probability denoted
By a numerical value from zero to one that measures the likelihood of an event occurring where zero means that the event is impossible, and one means that it is definitely occurring.
What is a sample space in probability
The collection of all possible alternatives in the experiment
What is an experimental probability?
A situation with a finite possible number of outcomes
What is an event in probability?
Any subset of outcomes in an experiment like you’re getting a passing grade out of ABCDEF or the event would be everything except F
What is a simple event in probability
An event that only contains one possible answer, one alternative of the set
When are events exhaustive?
When all alternatives of the sample space is contained in one or another event
When are events, mutually exclusive?
When the alternatives in an event do not occur in other events
What does this expression mean in probability?
C=A u B
That event C is a union of A and B containing everything in both A and B
What does this expression mean in probability
C=AnB
That event C is an intersection of A and B. The alternatives in C are the ones that exist in both A and B.
What does this expression mean in probability.
B=A^c
B is a complement of event A .That B contains all alternatives in the sample set that are not in the event A
What does this mean in probability? Ø
Null, a.k.a. an empty event
What is the sum of the probabilities of any list of mutual exclusive, and exhaustive events?
1
What is subjective probability?
An assignment of probability without assessing any data
What is classical probability?
The assumption that outcomes of an experiment are equally likely
What is empirical probability?
The relative frequency of occurrence is observed
Which probability categories are considered objective probabilities
Classical and empirical probability
What is the law of large numbers?
That his numbers get larger, the empirical probability comes closer to classical probability or the odds
If the odds are 1:9 what is the probability of the thing to succred
1/(1+9)=0.1
What is the complement rule of probability?
That probability of the complement of an event is equal to one minus the probability of the event
What is the addition rule in probability
The probability of the union of two events is equal to the sum of the probability of the two events minus the probability of the intersection. If the events are mutually exclusive the intersection is zero so you can simply add to the probabilities of the two events
What is the probability of an event that is conditional to another
The probability of their intersection, divided by the probability of the other event
What does this mean? P(A|B)
The probability of a conditional on B, the likelyhood of A occurring if B has occurred
How do you test if an event is dependent or independent of another event
If the probability of the event conditional to the other event is equal to the probability of the first event, they are independent of each other otherwise, they are dependent
What is the multiplication rule in probability
The probability of an intersection between two events is equal to the probability of one event called conditional to the other occurring multiplied by the other event occurring
If two events are independent, what is the probability of their intersection?
The probability of each event multiplied with the other
What is a contingency table?
Table where each slot in the rows and columns, have a meaning, and each space represent a unique combination of the rows and columns values
What’s the joint probability table?
A contingency table where each value it is the probability of the intersection of the row and column events also called joint probability or marginal probability
What is the total probability rule?
The probability of an event is equal to the probability of its intersection with another event, and it’s intersection with that events complement
When do you use Baier’s theorem?
When you want to upgrade a prior probability to a posterior or probability that is affected by another event
What decides if you are going to use the combination formula or the permutation formula
Use the permutation formula when calculating the number of ways to choose a number off, objects from a total N number of objects if the order in which the objects are listed, it does matter and use the combination formula if it doesn’t matter.
