Name: ______________________________ Date: __________________ AIM: SWBAT to find the probability of a single event.
DO NOW:
Change each fraction into a decimal and a percent.
1) 1
2 ______, ______ 2) 1
4 ______, ______ 3) 1
5 ______, ______
CLASSWORK:
Probability is the likelihood an event will happen; written as a ratio (fraction). Probability of an event = number of ways the event can occur
number of possible outcomes What is an outcome?
An outcome is the possible result of an action.
For example: You roll a die. There are ____ possible outcomes. What is a sample space?
Sample space is a list of all the possible outcomes.
For example: You roll a die. The sample space is ________________
The probability of a chance event is a number between 0 and 1 that expresses the likelihood of the event occurring. Greater numbers indicate greater likelihood. A probability near zero
indicates an unlikely event, a probability around 1
2 indicates an event that is equally likely to happen or not happen, and a probability near 1 indicates a likely event.
Describe the likelihood of an event as impossible, unlikely, equally likely, likely or certain.
1) Your soccer team wins 3
4 of the time. _________________
2) There is a 0% chance that you will grow 12 more feet. _________________ 3) The probability that the sun rises tomorrow is 1. _________________
4) It rains on 1
5 of the days in July (hint: figure out % first). _________________ 5) There is a 5% chance of winning a contest. _________________
Find each probability as a FRACTION in SIMPLEST FORM, if you roll a standard die. P (1) means “The probability of getting a 1 is?” _________
P (2) = _________
P (1 or 2) = _________ NOTE: “OR” means addition P (not a 4) = _________
P (even number) = _______ P (prime number) = _______ P (composite number) = _______ P (1, 2, 3, 4, 5 or 6) = _________ P(not a 7) = _________
This is known as a _______ event.
P (7) = _________ P(not a 1, 2, 3, 4, 5, or 6) = _________ This is known as an __________ event.
What is theoretical probability?
Theoretical probability describes how likely it is that an event will happen based on all the possible outcomes. It is what SHOULD happen and uses the ratio:
P (event) = Number of ways the event can occur Number of possible outcomes
All of the problems above about rolling the standard die are theoretical probability (because you’re not actually doing it).
What is experimental probability? (conduct an experiment)
Experimental probability is the probability based on experimental data that are found by repeating the experiment several times. It is what ACTUALLY happened and uses the ratio:
Number of possible outcomes
If we rolled a standard die 100 times and recorded the results that would be an example of experimental probability.
# on die 1 2 3 4 5 6
# of rolls 1 6
20 13 17 19 15
Find the experimental probability of each event.
P (1) = _________ P (2) = _________ P (4) = _________ P (6) = _________
Standard Deck of Cards - _______ Cards
Clubs; Black - _______ cards
Spades; Black - _______ cards _________ Black Cards Hearts; Red - _______ cards
Diamonds; Red - _______ cards _________ Red Cards Face cards are kings, queens, & jacks
Each suit (clubs, spades, hearts, and diamonds) has number cards 2 – 10 and an ace. Find each probability. Express your answer as a fraction in SIMPLEST FORM.
1) P (red card) = _________ 2) P (spade) = _________ 3) P (5) = _________
7) Is this an example of experimental or theoretical probability? ______________________ (Hint: you’re not actually pulling a card from the deck)
A bag of marbles contains: 1 green, 2 blue, 1 yellow, 3 purple and 3 red.
1) How many possible outcomes are there? (count the # of marbles in all) _______ 2) How many marbles are in the sample space? _______
3) P (blue) = ______ 4) P (not red) = ______ 5) P (green) = ______ 6) P (not blue) = ______ 7) P (purple) = ______ 8) P (blue or red) = ______ 9) P (yellow) = _____ 10) P (orange) = ______ 11) P (not pink) = ______ 12) Is this an example of theoretical or experimental probability? ____________________ (Hint: you’re not actually pulling the marbles from the bag)
Ben draws a pen at random from a bag of pens. He records its color and replaces it. His results are shown in the table below.
Pens Blue Red Black
Frequency 29 19 27
13) How many times was the experiment conducted? (count the frequency) ___________
14) What was the experimental probability of getting a black pen? ___________ 15) What was the experimental probability of getting a blue pen? ___________
Describe the likelihood of an event as impossible, unlikely, equally likely, likely or certain. (see the chart on page 1 to guide you)
16) Randomly picking a green card from a standard deck of playing cards. ________________
Name: __________________________ Date: ______________ HOMEWORK – PROBABILITY OF A SINGLE EVENT Period 7
Directions: Express each probability as a fraction in SIMPLEST FORM!
There are 3 blue marbles, 6 red marbles, 2 green marbles and 1 black marble in a bag. Suppose you select one marble at random. Find the probability for each of the following. 1) P (a blue marble) = ________ 2) P (a black marble) = ________
3) P (a green marble) = ________ 4) P (a red marble) = ________
5) P (not a green marble) = ________ 6) P (a blue or red marble) = ________ 7) P (a green, red or black marble) = ________ REMEMBER OR MEANS ADD! 8) P (not a red marble) = ________
9) P (a yellow marble) = ________ This is an ________________ event. (impossible, unlikely, equally likely, likely, certain) 10) P (not an orange marble) = ________ This is a ________________ event.
(impossible, unlikely, equally likely, likely, certain)
Suppose you draw one card at random from a standard deck of 52 playing cards. Find the probability for each of the following as a FRACTION in SIMPLEST FORM. 11) P (the five of hearts) = ________ 12) P (the queen of diamonds) = ________ 13) P (a black card) = ________ 14) P (not a black card) = ________
15) P (a jack) = ________ 16) P (an eight, a nine or a ten) = ________ 17) P (a diamond or a club) = ________ 18) P (not a heart) = ________
Describe the likelihood of an event as impossible, unlikely, equally likely, likely or certain. 21) There is a 0% chance of picking a 13 in a deck of cards. _________________
22) There is a 50% chance of picking a red card in a deck of cards. _________________ 23) There is an 80% chance of snow tomorrow. _________________
