Stats 4 Day 7b
SILENT DO NOW
ON DESK:
Agenda:
pen/pencil
Quiz Corrections
Probability Book
Definitions
Quiz
W/O Replacement Lesson
Ch. 15 Notes
Board Work/WS/ET
DO NOW:
Quiz Corrections + Continue Probability Book
Ch. 14
Homework due Thursday:
Ch. 15 #3-6, 19, 20
What we know and
where we are going…
•
•
We know from Chapter 14 how to
calculate probability for disjoint,
independent events using 4 rules
Now we will discover how to
calculate probabilities for nondisjoint sets and for dependent
events (in Chapter 15)
Definitions
•
What was disjoint again??
The two events cannot happen at the same time
Ex. Having a car, not having a car
yellow and an orange starburst
•
OR
pulling a
What did it mean to be independent
again??
One event does not affect the other
Ex. Gender and GPA
Independence and
Disjoint
•
YES!!
•
•
Disjoint
NO!!
Mutually Exclusive
P(A B)= 0
Can occur together
P(A B) = 0
•
Does NOT affect the other
YES!!
event
•
•
•
Independent
NO!!
DOES affect the other event
Example
Explain why the following are
•
Disjoint and/or Independent
•
1) probability of being a tall person
(over 5’10”) and a boy
• 2) probability of rolling a 3 and a 4
• 3) probability of pulling a black and a
jack from a deck of cards
• 4) wearing glasses and girl
• 5) wearing glasses and age
• 6) studying spanish and french
•
Some Probability for
Thought….
•
•
1) I am playing a game with you where if you
get 3 chances to pull an ace. I put back the
card after you pull it and ask you to pull again,
then repeat. What is the probability of pulling
3 aces if there are 4 aces out of the 52 cards?
2) If I don’t replace the cards, what happens
to the probability?
Again…
•
•
•
An issue of INDEPENDENCE!
THIS IS PROBABILITY WITHOUT
REPLACEMENT
Getting a “success” on the first
affects the probability of the second
since the total changes
More Examples
•
There are 10 starbursts in a bag. 5
are red, 2 are pink, 2 are yellow, 1
orange.
If you pull 3, what’s the probability all
red?
• None are pink?
• First is red and the rest are pink?
•
Worksheet in Groups
Stats 4 Day 8b
SILENT DO NOW
ON DESK:
pen/pencil
Notebook
WS
Agenda:
Do Now- Ch 14
Finish W/O Replacement
Board Work + ET
Nondisjoint Lesson
DO NOW:
Ch. 14 Review ½ Sheet
Homework due Thursday:
Ch. 15 #3-6, 19, 20
Review
In a bag of 10 starburst, 2 are yellow,
4 are pink, 3 are red, and 1 is orange.
If I pull 3 from the bag,
• 1) what is the probability they are all
pink?
• 2) P( first pink, then red, then yellow)
• 3) P(none yellow)
• 4) P(at least one yellow)
•
Practice
•
1. Finish Worksheet in Color Groups
• (6
•
min)
2. In pairs or groups of 3, board work
• (15
•
min)
3. Exit Ticket (graded)
• (10
min)
Some more Probability
for Thought….
•
1) Is the following probability table
possible? Why or why not?
x
P(x)
Like Video
Games
52%
Like Reading
31%
Like Both
14%
Like Neither
31%
When the events are
not disjoint…
•
What was disjoint again?
When events cannot occur at the same
time (ex. rolling a 3 and a 4 on the same
roll, liking dogs and not liking dogs.etc)
•
What word clues us in to add again?
OR
Non Disjoint Events
•
•
Non-disjoint events:
When the events can occur at the
same time (the probabilities may add
to over 100%)
We asked 100 people what school
sports teams they play on:
• 30% said they played football
• 45% said they played basketball
• 35% said they played volleyball
•
•
What’s going on here…
Addition Rule for
Non-Disjoint Events
P(A OR B) = P(A U B)
• where event A and event B are nondisjoint:
•
•
•
=P(A) + P(B) – P(A
B)
What is the probability of pulling a
red card or an ace??
Steps:
1. Define event A and event B
2. Determine P(A), P(B), P(A
B)
3. Make a Venn Diagram
4. Determine what the question wants
•
Practice
•
79% of Pritzker students are in a nonathletic club after school, 38% of Pritzker
students are in an athletic clubs, and 18%
are in both.
1) What is the probability a pritzker
student is in neither?
• 2) What is the probability a student is just
an athlete?
• 3) What is the probability a student is an
athlete or in a club?
•