bell work determine the total number of outcomes (combinations). 1) you are picking an outfit from...
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Bell WorkDetermine the total number of outcomes (combinations).
1) You are picking an outfit from the following list of clothes. If you choose one hat, one shirt, one pair of pants, and one pair of socks, how many total outfits could you make?Hats Shirts Pants Socks
BlueGreenYellow Black
PinkNeon GreenStriped
JeansCorduroys
Polk-a-dot“Bacon”Rainbow Toe-socks
Total Number of Hat Options: 4Total Number of Shirt Options: 3Total Number of Pants Options: 2Total Number of Socks Options: 3
4 x 3 x 2 x 3 =72
72 Outfits!
Tree Diagrams
•Way of organizing and visualizing outcomes
• Useful when the experiment happens in stages
• They can help you calculate probabilities
How many different ways can a red, blue and green marble be pulled from a
bag?
Solve using a Tree Diagram
How many different ways can a red, blue and green marble be pulled from a bag?
Chance Experiment:
Sample Space:
Total Number of Outcomes:
1
2
3
4
5
6
Pulling a Marble from a bag
Red, Blue, Green
6
How many different ways can a red, blue and green marble be pulled from a
bag?Try making an organized list
(R,B,G)(R,G, B)(G, R, B)(G, B, R)(B, G, R)(B, R, G)
HH HTTH TT
H TH
T
Making a TableYou flip a coin twice.
Make a table to display your outcome.
Why can’t we can’t we use this method for the problem where we draw marbles out of a bag?
Independent and Dependent EventsTell whether the events are independent or dependent.
You randomly draw a number from a bag. Then you randomly draw a second number without putting the first number back.
b.
You roll a number cube. Then you roll the number cube again.
a.
The result of the first roll does not affect the result of the second roll, so the events are independent.
There is one fewer number in the bag for the second draw, so the events are dependent.
You TryIn Exercises 1 and 2, tell whether the events are
independent or dependent. Explain your reasoning.
1. You toss a coin. Then you roll a number cube.
You randomly choose 1 of 10 marbles. Then you randomly choose one of the remaining 9 marbles.
2.
The coins toss does not affect the roll of a dice, so the events are independent.
There is one fewer number in the bag for the second draw, so the events are dependent.
1 1P(head and tail)
21
=2 4
x
1 1P(tail and tail)
21
=2 4
x
12
head
tail
First Coin Second Coin
head
tail
head
tail
12
12
12
12
12
1 1P(head and head)
21
=2 4
x
1 1P(tail and head)
21
=2 4
x
Peter tosses two coins.
(a)Draw a tree diagram to show all possible outcomes.
(b) Use your tree diagram to find the probability of getting
(i) 2 Heads
(ii) A head or a tail in any order.
P(2 heads) = ¼
P(head and a tail or a tail and a head) = ½
Independent Events
2 Independent
Events.
3 Selections
710
310
First Draw Second Draw
red
red
blue
red
red
red
red
blue
blue
blue
blue
red
blue
blue
Third Draw
You choose a colored chip and then replace it. Finish the tree diagram for the second and third draw.
310
310
710310
710
710
310
710
310
710 3
10
710