2 Probability

Question 1

What is the definition of an experiment in probability?

Answer 1

A process that yields an outcome.

Question 2

What is an event in probability?

Answer 2

A set of outcomes.

Question 3

Define sample space.

Answer 3

The set of all possible outcomes.

Question 4

What does complement refer to in probability?

Answer 4

The set of outcomes which are not contained in an event.

Question 5

Describe A’

Answer 5

The is the event NOT A

Question 6

What are mutually exclusive events?

Answer 6

Two events that share no common outcomes.

Question 7

What does it mean for two events to be statistically independent?

Answer 7

The occurrence of one event does not affect the probability of the other event.

Question 8

What is the formula for independent events?

Answer 8

Question 9

What is the range of probabilities for all events?

Answer 9

Between 0 (impossible) and 1 (certain).

Question 10

What is the sum of all probabilities in any experiment?

Answer 10

1

Question 11

What is the complement of the event ‘The coin lands on heads’?

Answer 11

The coin lands on tails.

Question 12

What is the complement of the event ‘the die shows an even number’?

Answer 12

The die shows an odd number.

Question 13

What is the complement of the event ‘I do not catch any of my trains on-time’?

Answer 13

I catch at least one of my trains on-time.

Question 14

What is the additional rule in probability?

Answer 14

Question 15

What is a Tree Diagram used for?

Answer 15

To show the outcomes of two (or more) events happening in succession.

Question 16

What is a Hyergeometric Tree?

Answer 16

A specific case of a tree diagram for sampling without replacement.

Question 17

What does ‘at least one’ refer to in probability?

Answer 17

The probability that one or more events occur.

Question 18

What does conditional probability depend on?

Answer 18

The outcome of a previous event

Question 19

What does the notation P(A|B) represent?

Answer 19

The probability of A occurring GIVEN that B has already occurred

This is a key concept in conditional probability.

Question 20

How do you calculate conditional probabilities?

Answer 20

By reducing the sample space

Question 21

What is the probability of two events A and B being mutually exclusive?

Answer 21

This means they cannot occur at the same time.

Question 22

What does it mean if events A and B are not independent?

Answer 22

P(A and B) ≠ P(A) x P(B)

This indicates a dependence between the events.

Question 23

What statistical formula is true if events A and B are independent?

Answer 23

P(A and B) = P(A) * P(B)

This indicates a dependence between the events.