Presentation on theme: "DATA, STATS, AND PROBABILITY Probability. ImpossibleCertainPossible but not certain Probability 0Probability between 0 and 1Probability 1 What are some."— Presentation transcript:
ImpossibleCertainPossible but not certain Probability 0Probability between 0 and 1Probability 1 What are some events that have a probability of 1? What are some events that have a probability of 0?
Probability The probability that an event will happen is given by the following formula: P (event) = number of favorable outcomes total number of outcomes
Probability A bag contains the following: 7 red marbles 6 green marbles 7 white marbles What is the probability of selecting a red marble? P (red) = number of favorable outcomes total number of outcomes 7 red marbles 20 total marbles = 7 20
Probability Two numbered cubes are rolled. What is the probability that the sum of their numbers will be equal to 7? How can their sum equal 7? 1 and 6 6 and 1 2 and 5 5 and 2 3 and 4 4 and 3 How many total outcomes are there when you roll two numbered cubes? 6 for Cube 16 for Cube 2= 36 total 6 36 P(7)== 1 6
Probability For the pair of spinners below, draw a tree diagram showing the outcomes when spinner 1 is spun and spinner 2 is spun. 12 3 12 34
Probability 12 3 12 34 If both spinners are spun, what is the probability that the sum will equal 5? P (sum equals 5) =
Probability If the probability of an event is 0, then: a) It is certain b) It is impossible c) It is probable but not certain d) It is probable but not impossible
Probability The probability the sun sets in the west is: a) 0b) 1c) -1d) ½
Worksheet from yesterday: Lesson 8.1 practice (1-25 odd)
Probability If you flip a coin, what is the probability that it lands on either heads or tails? This is an example of an “or” statement
Probability “Or” statements: An “or” statement will increase the number of favorable outcomes without increasing the total number of outcomes → increases the probability of an event
Probability Suppose you roll a pair of numbered cubes. What is the probability that the two numbers are equal or their sum equals 7? Equal: 1 and 1 2 and 2 3 and 3 4 and 4 5 and 5 6 and 6 Sum = 7 6 and 1 1 and 6 2 and 5 5 and 2 3 and 4 4 and 3 Prob. = 12 36 = 1 3
Probability Suppose you select a card at random from a standard deck of cards. Find the probability that it is: P (ace of spades) = 1 52 P (heart) = 13 52 1 4 = P (heart or ace of spades) = 14 52 7 26 =
Probability Probability of multiple events If you flip a coin, what is the probability that the coin will land on heads? If you flip the coin again, what is the probability that it will land on heads again? What is the probability of flipping a coin twice and having it land on heads twice?
Probability When you are finding the probability of multiple events: 1) Find the probability of each event separately 2) Multiply the two probabilities together 3) Reduce to lowest terms
Probability You flip a coin and roll a numbered cube. What is the probability of the coin landing on tails and the numbered cube landing on 4? P (tails) =P (4) = P (tails & 4) =
Probability You pick two cards at random from a standard deck of cards without replacing them. What is the probability that you pick a red card followed by a black card? P (red) =P (black) = P (red, black) =
Probability A deck of cards has 4 orange, 5 pink, and 5 yellow cards. You pick 3 cards from the deck. Cards are not returned to the deck after they are picked. What is the probability the first card is yellow, the second card is pink, and the third card is orange? P (y.) =P (p.) = P (y,p,o) = P (o.) =
Probability Classwork / homework if you do not finish: Worksheet on probability of single and multiple events.