Transcript Probability - mslockwoodmath

Probability
LESSON 5.7
Socrative (12/9)
 You choose a card out of a standard deck.
P(diamond)?
 You roll 2 fair dice. P(5 or 7)?
 The chance it will rain tomorrow is 37%. What is the
probability of its complement?
 A plush Minnie Mouse doll is on sale for $20.00.
The original price was $30.00. What is the discount
rate? Please write your answer to the nearest whole
percent.
A compound event is made up of one or
more separate events.
•To find the probability of a compound event, you
need to know if the events are independent or
dependent.
Events are independent events if the
occurrence of one event DOES NOT affect
the probability of the other.
Events are dependent events if the
occurrence of one event DOES affect the
probability of the other.
Practice
1. P(roll even #, spin odd) =
2. P(roll a 2 or 3, spin a 7) =
3. P(roll a 7, spin an even #) =
4. Are these events independent or dependent?
Solving Probabilities:
 P( a AND b) : P(A) * P(B given A)
 P(a OR b) : P(A) + P(B)
 Relative Frequency: the probability of an event that
actually occurred- written as a percent or fraction.
 Theoretical Probability: Probability of events that
SHOULD occur mathematically.
Probability:
Uncopyrightable
P(vowel):
P(vowel, then immediately pulling out another vowel):
P(consonant):
P(vowel or consonant):
P(A, not putting it back, then U):
 10 socks are in a drawer: 3 red, 4 blue, 3 white.
What is the probability that you will pick a red sock
and then pick a blue sock ?
What is the probability that you will pick a red sock,
return it to the drawer, then pick a blue sock?
A coin and a die
 P(heads, even #):
 P(tails, # less than 3):
 P(tails, 5 or 6):
You Try…
Use the table to find the probability of each event.
Outcome
A
Probability 0.3
1. P(C)
2. P(not B)
B
0.1
C
0.4
3. P(A or D)
D
0.2
4. P(A and C)
Remember:
Or means to add the probabilities together.
Not means add all of the other probabilities together.
And means to multiply the probabilities.