Transcript Do Now 1/4/08

Do Now 3/5/10
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Take out HW from last night.
 Progress
reports
 Scale drawings
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Copy HW in your planner.
 Textbook
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page 309, #7-11 all, 17 & 18
Did you hand in POTW #5?
Objective
SWBAT find the probability 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.
Outcome
the possible results of an experiment
Event
an outcome or collection of outcomes
“Odds”
Odds
the ratio of the number of outcomes to outcomes.
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
“Experimental Probability”
Draw the following circle chart on
your paper. Shade in the blue
areas on your chart with your
pencil.
Using your pencil and a paperclip
spin your spinner 8 times. Record
the number of times where
the spinner stopped.
Do your experimental outcomes
match the theoretical outcomes?
Why or why not?
“Probability of an Event”
# of favorable outcom es
P
Total # of outcom es
“Theoretical Probability”
A probability is always written as a ratio or fraction
Number of RED regions
5
8
Total number of regions
What is the probability (your chances)
of landing is
the spinner on a RED region?
How many denominations
How about a BLUE How
region?many are RED?
the whole broken up into?
“Interpreting Probabilities”
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The probability of something occurring is
always between 0 and 1.
Likely
to occur
Unlikely
to occur
0
Impossible
0.25
0.5
Occurs ½
the time
0.75
1
Certain to
occur
“Roll the Dice”
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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 outcom es
Total # of outcom es
P
6 1

36 6
What is the probability that you will
roll a prime number? a composite
number?
P
15 5
# of favorable outcom es
P

Total # of outcom es
36 12
P
21 7
# of favorable outcom es
P

Total # of outcom es
36 12
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NJASK7 Prep
Homework
 Textbook
page 309, #7-11 ALL and 17 & 18
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