7th 7 Probability Mid Topic Relearning Lesson

​Terms:​

1. ​Outcomes: Possible results of an event.

2. ​Probability: Likelihood of an outcome expresses as percent, fraction or decimal.

3. ​Fair Event: Each outcome has the same probability.

4. ​Theoretical Probability: What should happen when doing an experiment.

5. ​Experimental Probability: What did happen during the experiment.

​7-1: Likelihood and Probability

​Outcomes: Red, Green, Yellow and Blue

​Probability of Green: 2/8 = 1/4 = 25%

​The spinner is fair because:

​P(Green) = P(Red) = P(Yellow) = P(Blue): All are 25%

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​7-2: Theoretical Probability

​Outcomes: Win, Lose

​Probability of Win: 2/16 = 1/8 = 12.5%

​Theoretical Probability can be used to make predictions.

• ​Theoretical Probability * Number of plays = Number of expected winners.

• ​So if 500 people played the game:

• ​12.5% * 500 = 62.5 expected winners.

​7-3: Experimental Probability

​Experimental Probability is the ratio of favorable events to the number of trials.

• ​Can be used to compare to the Theoretical Probability, make predictions.

• ​If the game is played 500 times with 50 winners, that is a 10% Experimental Probability or Relative Frequency.

• ​This is close to the Theoretical Probability of 12.5%

​7-4: Probability Models

​Sample Space: List of all possible outcomes.(with repeats)

​Probability Model: Sample space and events with probabilities.

​

​For the jar on the right Probability mode:

Sample Space {R,G,G,G,P,P,P,P,P,P}

​P(R) = 1/10, P(G) = 3/10, P(P) = 6/10.