Chapter 4 terms Flashcards
Conditional probability
Event A occurs given Event B has occurred
“the chance of observing one of the elements in A, from the set of elements in B only”.
P(A|B) = P(AnB)/P(B)
= P((AnB)/sample space)/(P(B)/sample space)
Partition theorem take 2
P(A) =E^m_i=1 P(AnB_i) = E^m_i=1 P(A|B_i)P(B_i)
probability trees
Useful when events happen in a sequence
Multiple across the branches
Eikosogram
A scaled representation of a two-way of counts. Displayed as a square. with side of length one
Independence
Knowing that B occurs does not affect the probability of A occurring.
P(A|B) = P(A)
P(B|A) = P(B)
Independent if P(AnB) = P(A) P(B)
if P(B|A) = P(BnA)/P(A) = P(A|B)P(B)/P(A) = P(B)
then
P(AnB) = P(A|B)P(B) = P(A)P(B)
Mutually exclusive
AnB = (/), which implies P(AnB) = 0