Transcript 9-2 Tree Diagrams (pgs 374-377)

9-2 Tree Diagrams
(pgs 374-377)
D7 : Compute probabilities using
tree diagrams
Example 1
A certain type of watch comes in brown or black and in a small
or large size. Find the number of color-size combinations that
are possible.
Make a tree diagram to show the sample space. Then give the
total number of outcomes.
Color
brown
black
Size
Sample Space
small
brown, small
large
brown, large
small
black, small
large
black, large
There are 4 different outcomes for the colors and sizes of the watch.
Example 2
Suppose Pablo tosses 3 coins. Find the probability of all three
coins landing on tails.
Make a tree diagram to show the sample space. Then give the
total number of outcomes, and the probability of all three
landing on tails.
Coin #1
Coin #2
heads
heads
tails
tails
heads
tails
Coin #3
heads
tails
heads
tails
heads
tails
heads
tails
Sample Space
heads, heads, heads
heads, heads, tails
heads, tails, heads
heads, tails, tails
tails, heads, heads
tails, heads, tails
tails, tails, heads
tails, tails, tails
1
There are 8 different outcomes for the coin toss.
The probability of all three coins landing on heads is 8.
You try…
A family has two children. Draw a tree diagram
to show the sample space of the children’s
genders. Then determine the probability of
the family having two girls.