Investigate chance processes and develop, use and evaluate probability models. NC.7.SP.6 Collect data to calculate the experimental probability of a chance event, observing its long-run relative frequency. Use this experimental probability to predict the approximate relative frequency. Clarification Checking for Understanding A bag contains 100 marbles, some red and some purple. Suppose a The focus of this standard is on relative frequency, which is the observed proportion of successful outcomes compared to the total number of trials for student, without looking, chooses a marble out of the bag, records the chance events. This standard connects probability models to chance events color, and then places that marble back in the bag. The student has related to sampling and sampling variability. recorded 9 red marbles and 11 purple marbles. Using these results, predict the number of red marbles in the bag. Students recognize that individual experimental results may vary for each separate trial, which may also differ from the long run probability. (Adapted from SREB publication Getting Students Ready for Algebra I: What Middle Grades Students Need to Know and Be Able to Do) Design a Probability Experiment: This standard is intended to use experimentation to show that over a large For example, give each pair of students a bag that containing 4 green number of trials that relative frequencies for experimental probabilities marbles, 6 red marbles, and 10 blue marbles. become closer to the theoretical probabilities. Each group performs 50 pulls, recording the color of marble drawn and replacing the marble into the bag before the next draw. Students should make predictions before conducting the experiment, run trials Students summarize their data as experimental probabilities and make of the experiment and refine their conjectures as they run additional trials. It is conjectures about theoretical probabilities. How many green draws appropriate to use graphing calculators or computer simulation programs to would be expected if 1000 pulls are conducted? 10,000 pulls? collect large amounts of data on chance events. Students record their data in a relative frequency table as they compile their results with the class. How did the relative frequencies Additionally, digital software can be used to conduct a large number of trials. change? The following are examples of online simulators that can be used: Optional: Students can create another scenario with a different ratio of marbles in the bag and make a conjecture about the outcome of 50 marble pulls with replacement. Return to:
Investigate chance processes and develop, use and evaluate probability models. NC.7.SP.6 Collect data to calculate the experimental probability of a chance event, observing its long-run relative frequency. Use this experimental probability to predict the approximate relative frequency. Clarification Checking for Understanding The focus of this standard is on relative frequency, which is the observed proportion of successful outcomes compared to the total number of trials for chance events. This standard connects probability models to chance events related to sampling and sampling variability. Students recognize that individual experimental results may vary for each separate trial, which may also differ from the long run probability. This standard is intended to use experimentation to show that over a large number of trials that relative frequencies for experimental probabilities become closer to the theoretical probabilities. Students should make predictions before conducting the experiment, run trials of the experiment and refine their conjectures as they run additional trials. It is appropriate to use graphing calculators or computer simulation programs to collect large amounts of data on chance events. Additionally, digital software can be used to conduct a large number of trials. The following are examples of online simulators that can be used: A bag contains 100 marbles, some red and some purple. Suppose a student, without looking, chooses a marble out of the bag, records the color, and then places that marble back in the bag. The student has recorded 9 red marbles and 11 purple marbles. Using these results, predict the number of red marbles in the bag. (Adapted from SREB publication Getting Students Ready for Algebra I: What Middle Grades Students Need to Know and Be Able to Do) Design a Probability Experiment: For example, give each pair of students a bag that containing 4 green marbles, 6 red marbles, and 10 blue marbles. Each group performs 50 pulls, recording the color of marble drawn and replacing the marble into the bag before the next draw. Students summarize their data as experimental probabilities and make conjectures about theoretical probabilities. How many green draws would be expected if 1000 pulls are conducted? 10,000 pulls? Students record their data in a relative frequency table as they compile their results with the class. How did the relative frequencies change? Optional: Students can create another scenario with a different ratio of marbles in the bag and make a conjecture about the outcome of 50 marble pulls with replacement. Return to: