Chapter 13.5 Venn Diagrams
and Probability
Name ________________________________
How can you count outcomes using a Venn Diagram?
Step 1- Collect Data
Use the Venn diagram shown. Ask the member of your math class if they play a musical
instrument, play on a school sports team, do both, or do neither. Write their names in the
appropriate part of the Venn diagram.
Step 2- Complete the frequency table
Complete the frequency table. When determining the frequency for a category, be sure to
include all the students in your math class who are in the category.
Draw Conclusions
Use your observations to complete these exercises.
1)
A student from your class is chosen at random. Find the probability of each event.
Explain how you found the probability.
a)
The chosen student plays a musical instrument.
b)
The chosen student plays a musical instrument and plays on a school sports
team
Disjoint events are events that have no outcomes in common. Overlapping
events are events that have one or more outcomes in common.
2)
Tell whether the events involving the spinner are disjoint or overlapping.
3)
The table shows the probability that an arena event is of the given type. What is the
probability that a randomly chosen event is an ice hockey game or a basketball game?
Two disjoint events in which one or the other must occur are called complementary events. If
event A and event B are complementary events and you know the probability of once event
you can use the following rule to find the probability of the other event.
4)
5)
At your school, 3% of the students know sign language.
a)
What is the probability that a randomly chosen students
does not know sign language?
b)
There are 267 seventh graders at your school.
Estimate how many do not know sign language.
On a subway, 30% of the passengers have briefcases. What is the probability that a
randomly chosen passenger does not have a briefcase?