Mrs. Hubbard 6 th Grade

 What is the chance that a particular event will happen? - It will rain tomorrow. - We will have school tomorrow. - We will take the DSTP. - You will hear your favorite song on the radio today.

 Events that are Certain of happening have a Probability = 1 or 100%.  Events that are Impossible or have NO CHANCE of happening have a probability = 0 or 0%  When we look at the Probability of an event occurring, we look at fractions, in between 01 Impossible Certain

 When we use Math to calculate the chances of something happening…. We are finding the Probability.  The probability can be calculated using the following formula.  P(E) = number of favorable outcomes number of possible outcomes

There are 2 possible outcomes: HEADS or TAILS. There is only 1 favorable outcome: HEADS The chance of getting a heads when we flip a coin is: ½

 If we flip a coin 10 times, how many times would you expect it to land on “heads”?  How about flipping it 20 times?  How about 50 times?  (Insert coin from smartboard)

Theoretical Probability *When we use Math to calculate the chance of something happening? Flipping a Coin = ½ Flipping a Coin 10 times, we can expect that it will land on heads 5 times. (1/2 of 10)  Experimental Probability *What actually happens when we experiment with the event. Even though we expected to get heads 5 times, how many times did we actually land on heads out of ten times?

Fact: As we increase the # of trials in our experiment, the experimental probability will get closer and closer to our theoretical probability.

Sample Space- the set of all possible outcomes of an event. The sample space of flipping a coin. S= Heads, Tails The sample space of rolling a die: S= 1,2,3,4,5,6 Trials- the number of times we do an experiment.

Independent Events DOES NOT Independent Events: When the outcome of one event DOES NOT effect the outcome of the other event. Dependent Events DOES Dependent Events: When the outcome of one event DOES effect the outcome of the other event.

Try to Decide Whether these events are Independent or Dependent. 1.Toss a coin. Then roll a number cube (die). 2. Select a card. Do not replace it. Then select another card. 3. Select a card. Replace it. Select another card. 4. Pick one flower from a garden, then pick another.

Probability of Two Independent Events Given a coin and a die, what is the probability of tossing a head and rolling a 5?

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