Probability - [Statistics 2]. Flashcards
If the Probability is equal to 0, what is said about it?
It is impossible to happen.
If the Probability is equal to 1, what is said about it?
It is certain to happen.
What equation allows you to estimate the P(A) by the relative frequency?
Relative Frequency (A) = Number of time event A occurs / Total number of trials.
What does P(A⋃B) mean?
What does it look like on a Venn Diagram?
A or B or both (All Parts).
Both A and B included aswell as the Intersection.
What does P(A⋂B) mean?
What does it look like on a Venn Diagram?
The intersection (both happening).
The intersection only between A and B.
What does A’ mean?
What equation can you use to help understand this?
What does it look like on a Venn Diagram?
Everything apart from inside of A.
P(A) + P(A’) = 1 OR P(A’) = 1 - P(A).
Everything outside of A is shaded.
What does P(B|A) mean?
What equation can you use to help understand this?
What does it look like on a Venn Diagram?
B given its in A.
P(B|A) = P(A⋂B) / P(A).
Has to be only within A’s circle but also has to be in B.
What’s the equation given in the formula booklet for the Addition Law?
P(A⋃B) = P(A) + P(B) - P(A⋂B).
What can we simplify the Addition Law to, for Mutually Exclusive Events?
NOT IN THE FORMULA BOOKLET!
What does it look like on a Venn Diagram?
P(A⋃B) = P(A) + P(B).
2 seperate circles which both are included.
What’s the equation given in the formula booklet for the Multiplication Law?
P(A⋂B) =P(A) x P(B|A).
OR
P(A⋂B) = P(B) x P(A|B).
THE ONE WITH P(B) IS NOT GIVEN IN THE FORMULA BOOKLET!
What’s the equation NOT given in the formula booklet for Independent Events?
P(A⋂B) = P(A) x P(B).
