Probability

Question 1

What is an experiment?

Answer 1

A repeatable process that produces outcomes

Question 2

What do you have to know before conducting an experiment?

Answer 2

All of the possible outcomes

Question 3

What is an outcome?

Answer 3

Result of a single trial of an experiment

Question 4

What is sample space?

Answer 4

Set of all possible outcomes on an experiment

Question 5

What is an event?

Answer 5

Collection, or set of one or more possible outcomes. Answers the question: what is the probability that something will happen?

Question 6

What is mathematical probability?

Answer 6

Idealisation based on imagining on what would happen in an indefinitely long series of experiments - not what will happen but what will probably happen

Question 7

What are the 2 types of events?

Answer 7

Mutually exclusive and independent

Question 8

What is a mutually exclusive event?

Answer 8

The two events have no possible outcomes in common

Question 9

What is an independent event?

Answer 9

When the occurrence of one event does not affect the probability of the other

Question 10

What scale is numerical probability measured on?

Answer 10

0-1

Question 11

What does 0 mean on a numerical probability scale?

Answer 11

The event is certain not to occur

Question 12

What does 1 mean on a numerical probability scale?

Answer 12

Event is certain to occur

Question 13

How do you calculate the probability of an event P(A)?

(classical way)

Answer 13

Number of possible outcomes in the event

/

Total number of possible outcomes

Question 14

What does compliment of A mean?

Answer 14

• Event A does not occur: A’ or A^c
• Outcomes not in A
• Event is everything but the event A

Question 15

What does intersection of two events A and B mean?

Answer 15

• A and B both occur together
• The intersection is when the outcome is both A and B

Question 16

What does union of two events A and B mean?

Answer 16

• At least one of A and B occurs
• Outcome is in either A or B or both

Question 17

What method do you use to find the probability of complement of A?

Answer 17

Subtraction

Probability of the complement of A is 1 minus the probability of A

Question 18

What method do you use to find out the probability of the union of two events?

Answer 18

Addition

When the outcome is either A or B you just add them together: P(A) + P(B)

When the outcome is in both A and B you have to add everything that occurs in A to everything that occurs in B and the minus everything that occurs in both

P(A) + P(B) - P(AuB)