Transcript Do Now 4/6/11

Do Now 4/6/11

Take out HW from yesterday.
 Textbook page 309, #3-7 all, 11a & b, 17 & 18

Copy HW in your planner.
 Practice worksheet 6.7, #1-14 all
 Practice worksheet 6.8, #1-12 all
 Quiz sections 6.5, 6.7, 6.8 Friday
8
In your notebook, find the probabilities using
the spinner at the right.

2 1

8 4
4 1

8 2
P(1 or 2) =
P(even) =
P(9) =

0
0
8
P(1-8) =
8
1
8
P(factor of 6) =
P(less than 4) =
4 1

8 2
3
8
1
7
2
6
3
5
4
Homework
Textbook page 309, #3-7 all, 11a & b, 17 & 18





3) 1/2
4) 1/2
5) 2/3
6) 11/15
about 268 days
7) 1/4




11a) 2/11
11b) 5/11
17) 16/143, or about 0.1119
18) 1/240 or about 0.0042
Objective
SWBAT find the odds of an event.
Section 6.7 “Probability and Odds”
Experimental probabilityperforming an experiment and testing
data.
Theoretical probabilitymathematically tells you how likely it is
that an event will happen.
“Probability of an Event”
# of favorable outcomes
P
Total # of outcomes
Section 6.7 “Probability and Odds”
Odds
the ratio of the number of outcomes to outcomes.
Two types of odds:
Odds in favor =
# of favorable outcomes
# of unfavorable outcomes
# of unfavorable outcomes
Odds against =
# of favorable outcomes
“What are the Odds?”
Odds in favor = # of favorable outcomes : # of unfavorable outcomes
Odds against = # of unfavorable outcomes : # of favorable outcomes
MATHEMATICAL
Each letter of the word above is written on a separate piece of paper and
placed in a hat. A letter is chosen at random from the hat.
What are the odds in favor of choosing a consonant?
7: 5
What are the odds against choosing a ‘M, A, T, or H’?
4: 8
1:2
Probability
Compares favorable
outcome to the TOTAL
number of outcomes.
# of favorable outcomes
P
Total # of outcomes
&
Odds
Compares outcomes to
outcomes.
Odds in favor =
Odds against =
# of favorable outcomes
# of unfavorable outcomes
# of unfavorable outcomes
# of favorable outcomes
Objective

SWBAT use the counting principle to find
probabilities
Roll the dice...

Suppose you are rolling a two 6-sided number cubes and
finding the sum of the rolls.
What is the probability that you
will roll a 7?
P
# of favorable outcomes
Total # of outcomes
P
6 1

36 6
What is the probability that you will
roll a prime number? a composite
number?
P
# of favorable outcomes
Total # of outcomes
P
15 5

36 12
P
# of favorable outcomes
Total # of outcomes
P
21 7

36 12
1
2
3
4
5
6
1
2
3
4
5
6
7
2
3
4
5
6
7
8
3
4
5
6
7
8
9
4
5
6
7
8
9
10
5
6
7
8
9
10
11
6
7
8
9
10
11
12
You are buying new eyeglasses and must choose
the frame material and shape. The frame can be either
plastic or metal. The shape can be rectangular, oval, cat’s
eye, or round. How many different frames are possible?
rectangular
oval
plastic
cat’s eye
round
One way to count the
number of possibilities is
to use a TREE DIAGRAM.
rectangular
metal
oval
cat’s eye
round
There are 8 different
frame types.
What if the frames come in different colors. They can be either
black, red, green, or blue. How many different frames are possible
now?
rectangular
rectangular
plastic
oval
plastic
oval
cat’s eye
cat’s eye
round
round
green
black
rectangular
rectangular
metal
oval
cat’s eye
round
rectangular
plastic
metal
oval
cat’s eye
There are
32 different
frame types.
round
rectangular
oval
plastic
oval
cat’s eye
cat’s eye
round
round
red
blue
rectangular
metal
oval
rectangular
metal
oval
cat’s eye
cat’s eye
round
round
Section 6.8 “The Counting Principle”
If one event can occur in m ways and
another event can occur in n ways, then
the two events can occur in mn ways.
The early bird menu at TGIFriday’s for lunch consists of 3 entrees and
2 desserts. How many different lunch combinations can you get?
Make a tree diagram:
E1
Use the Counting Principle:
E2
E3
D1
D2
D1
D2
D1
E1D1
E1D2
E2D1
E2D2
E3D1
6 lunch combinations
(3 entrees) x (2 desserts)
D2
E3D2
= 6 lunch combination
Use the Counting Principle with Probabilities
You spin each spinner once. Find the probability
that all three spinners stop on the number 2?
8
Use the counting principle
to find the total number of
possible outcomes.
Spinner 1 = 8 outcomes
Spinner 2 = 5 outcomes
Spinner 3 = 4 outcomes
The total amount of outcomes is
8 x 5 x 4 = 160.
5
1
7
2
6
3
5
4
2
1
4
4
1
3
2
3
The probability that all three spinners stop on the number 2
is 1/160.
Guess the Password?

You forgot your password to get into your
email. You remember that it is 3 uppercase letters and 3 numbers. What is your
probability of guessing it correctly?
A
26 outcomes
B
26 outcomes
C
26 outcomes
The total outcomes would be 17,576,000.
The probability would be 1 : 17,576,000.
1
10 outcomes
2
10 outcomes
3
10 outcomes
NJASK7 Prep
Homework
 Practice
worksheets 6.7 & 6.8