M12: Understanding Probability

Question 1

Probability of an outcome

Answer 1

Proportion of times the outcome would occur in a very long series of independent trials

Question 2

Independent trials

Answer 2

The outcome of any one trial is not affected by the outcome of any other

Question 3

Sample space

Answer 3

The set of all possible outcomes

Question 4

Event

Answer 4

An outcome or group of outcomes (Subset of sample space)

Question 5

Probabilities are between 0 and 1

Answer 5

Sum of all outcome probabilities must equal 1

Question 6

Complement of an event on SAME TRIAL

Answer 6

P(A) + P(A’) = 1

Question 7

Intersection of two events A and B on SAME TRIAL

Answer 7

Overlap
P(A&B)

Question 8

Union of two events A and B on SAME TRIAL

Answer 8

P(AUB) = P(A) + P(B) - P(A&B)

Question 9

Independence of two events on SEQUENTIAL TRIALS

Answer 9

P(A&B) = P(A)*P(B)