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Probability from an Experiment

Use the probability to predict how often it happens.

ExampleThe probability of getting a blue counter on a bag of counters is 0.4. Maria plans to try it 100 times. About how many times should Maria expect a blue counter, and would exactly that number be surprising?
0.4 × 100 = about 40 times
Answer: about 40 times
Getting exactly that number would not be surprising, but neither would a result a little above or below it — probability predicts the long-run rate, not the exact count of one experiment.
  1. 1.The probability of getting heads on a coin is 0.3. Maria plans to try it 100 times. About how many times should Maria expect heads, and would exactly that number be surprising?
    Answer: times
  2. 2.The probability of getting red on a spinner is 0.4. Ava plans to try it 150 times. About how many times should Ava expect red, and would exactly that number be surprising?
    Answer: times
  3. 3.The probability of getting a blue counter on a bag of counters is 0.5. Ethan plans to try it 150 times. About how many times should Ethan expect a blue counter, and would exactly that number be surprising?
    Answer: times
  4. 4.The probability of getting a blue counter on a bag of counters is 0.25. Ava plans to try it 150 times. About how many times should Ava expect a blue counter, and would exactly that number be surprising?
    Answer: times
  5. 5.Liam uses a bag of counters 250 times and gets a blue counter 101 times. Estimate the probability of getting a blue counter, and say why more trials would make the estimate better.
    Answer: