Chap 4: Probability

Question 1

complement rule

Answer 1

P(A) + P(not A) = 1

Question 2

intersection

Answer 2

both A and B

Question 3

union

Answer 3

either A or B

Question 4

mutually exclusive

Answer 4

both events can’t occur simultaneously

P(A and B) = 0

Question 5

collectively exhaustive

Answer 5

one of events must occur
P(A or B) = 1
P(A or B) not collectively exhaustive

Question 6

marginal rule

Answer 6

P(A) = P (A and B1) + P (A and B2) +…..+ P(A and Bk)

Question 7

joint probabilities

Answer 7

the chance that two or more outcomes occur together

P(A and B)

Question 8

addition law

Answer 8

P( A or B) = P(A) + P(B) - P(A and B)

Question 9

addition law in case A, B are mutually exclusive events

Answer 9

P(A or B) = P(A) + P(B)

Question 10

Condition law

Given the occurrence of B —> the probability of A is

Answer 10

P(A/B) = P(A and B) / P(B)
P(A and B) = joint probability of A and B
P(A)= marginal probability of A
P(B) = marginal probability of B

Question 11

A, B are independent event

Answer 11

P(A/B) = P(A)
P (B/A) = P(B)
P(A/B) = P(A) = P(A/not B)
P (A and B) = P(A) x P(B)

Question 12

Multiplication law

Answer 12

to calculate the intersection of two events
P (A and B) = P(B) x P(A/B)
P (A and B) = P(A) x P(B/A)