Probability M2A:2

Question 1

Marginal probability is represented by what symbol?

What is it’s conditions of independence?

Conditions of Dependence ?

Answer 1

Symbol: P(A)

Independance P(A)

Dependence P(A)

Question 2

Joint probability is represented by what symbol?

What is it’s conditions of independence?

Conditions of Dependence ?

Answer 2

Symbol: P(AB)
Independence: P(A) x P(B)
Dependence P(A|B) x P(B)

Question 3

Conditional probability is represented by what symbol?

What is it’s conditions of independence?

Conditions of Dependence ?

Answer 3

Symbol: P(A|B)

Independent: P(A)

Dependent: P(AB)
———
P(B)

Question 4

What is A Û B

Answer 4

This is a union

The union of A and B are elementary events that belong to either as or B or Both

Question 5

What is A (upside down U) B

Answer 5

The intersection of A and B elementary events that belong to both A and B

Question 6

If A and B are mutually exclusive, then the probability that A or B (the union of A and B) will occur is:

And if they are not mutually exclusive?

Answer 6

Mutually exclusive:

P(A Û B) = P(A) + P(B)

Not exclusive

P(AÛB) = P(A) + P(B) - P(A upside down U)B)

Where A (upside down U) B is the joint probability of A and B occurring together