Probability

Question 1

Trial

Answer 1

An experiment in probability

Question 2

Outcomes

Answer 2

The things that can happen in a trial

Question 3

Event

Answer 3

A group of one or more outcomes

Question 4

Sample-space diagram

Answer 4

A 2D grid combining the outcomes from 2 events

Question 5

P(A’)

Answer 5

The probability of A not happening

Question 6

Addition Law

Answer 6

P(A) + P(B) = P(A U B) + P(A ∩ B)

Works the same if every A and/or every B is negated

Question 7

Solving addition law problems

Answer 7

Draw a venn diagram and then rearrange the law with the relevant negation

Question 8

Probability tree

Answer 8

Shows probabilities for sequences of 2 or more events, label events above the branches that represent it

Question 9

Venn Diagram layout

Answer 9

Have the circles inside a rectangle with an S in the top corner

Question 10

Two way table

Answer 10

Labels the amount of each combination in a 2D table with a total column/row at the end for the totals of each row/column

Question 11

Mutually exclusive events

Answer 11

Events that cannot happen at the same time

Question 12

P(A ∩ B) for mutually exclusive events

Answer 12

0

Question 13

Venn diagram for mutually exclusive events

Answer 13

Two non-overlapping circles in the sample space

Question 14

Showing two events are mutually exclusive

Answer 14

Using the addition law to show that P(A ∩ B) is 0

Question 15

Independent events

Answer 15

Where the outcome of a second event doesn’t depend on whether another event has happened or not

Question 16

P(A ∩ B) for independent events

Answer 16

P(A) x P(B)

Question 17

Showing that events A and B are independent

Answer 17

P(A ∩ B) = P(A) x P(B)

Question 18

P(B | A)

Answer 18

The probability of B given A

Question 19

P(B | A) formula

Answer 19

P(A ∩ B)/P(A)

Question 20

Product Law for Conditional Probability

Answer 20

P(A) X P(B | A) = P(A ∩ B)