chapter 16 - conditional probability

Question 1

P(A∪B)

Answer 1

= P(A) + P(B) - P(A⋂B)
if mutually exclusive = P(A) + P(B) as P(A⋂B) = 0

Question 2

P(A|B)

Answer 2

= P(A⋂B) / P(B)
if independent = P(A)

Question 3

P(A⋂B)

Answer 3

P(B) * P(A|B) = P(A) * P(B|A)

Question 4

modelling assumptions

Answer 4

all outcomes equally likely
probability doesnt change over time