Geometry Unit 7
Conditional Probability
Name: ______________________
Period: ______
Use this Venn Diagram to fill in the table below. The first row has been completed for you.
A
B
6
4
7
3
EX.
1.
2.
Notation
Description
P (A  B’ )
Probability that it is
in A and not in B
P(AuB)
P (A  B’ )
Probability it is in the A or
both
3.
P (A B )
4.
P(A'|B)
5.
P (B’ | A )
Probability Event B will not occur,
given Event A
6.
P (B | A )
Probability Event B will occur,
given Event A
Probability it is not in A,
given that it is in B
Probability Event B will occur,
NOT given Event A
P(B| A')
Probability
6
3
or
20
10
Probability it is in A B
or both
Probability of Not
7.
Shading
17/20
9/10
10/20
1/2
3/20
1/10
14/20
7/10
6/20
3/10
13/20
4/11
Use this information for #8-11.
80% of people can swim. 70% of people can whistle. 55% of people can do both.
8. What percentage of people can swim or whistle?
95%
9. What percentage of people can neither swim nor whistle?
5%
10. What is the probability that a person can swim, given that he or she can whistle?
(You may find it helpful to sketch a Venn diagram first.)
5.5/10
11. What is the probability that a person can whistle, given that he or she can swim?
(You may find it helpful to sketch a Venn diagram first.)
70%