Events

Question 1

event

Answer 1

in a collection of sample points, an event occurs if any of the sample points in the event occurs

Question 2

probability

Answer 2

sum of probabilities of the sample points in the event

Question 3

complement of an event

Answer 3

the event consisting of all sample points that are not in the original event

Question 4

union of 2 events

Answer 4

event consisting of all sample points that are in either of the original events (denoted A U B)

Question 5

intersection of 2 events

Answer 5

event consisting of all sample points that are in both of the original events (denoted A upside down U B)

Question 6

addition law

Answer 6

P(A U B) = P(A) + P(B) - P(A intersects B)

Question 7

mutually exclusive events

Answer 7

events that have no sample points in common

Question 8

addition law for mutually exclusive events

Answer 8

P(A U B) = P(A) + P(B)

Question 9

conditional probability

Answer 9

P(A|B) = P (A Intersects B) / P(B)

and

P (B|A) = P( A intersects B) / P(A)

Question 10

multiplication law

Answer 10

P (A intersects B) = P(A) x P(B)

and

P(A intersects B) = P(B |A) x P(A)

Question 11

Independent events

Answer 11

if
P(A|B) = P(A)
and
P(B|A) = P(B)

Question 12

multiplication law for independent events

Answer 12

P (A intersects B) = P(A) x P(B)

Question 13

bayes’ theorem

Answer 13

P(Ai |B) = P(Ai) P(B|Ai) \ P(B)