Develop a probability model and use it to find probabilities of events. Compare probabilities from a model to observed frequencies; if the agreement is not good, explain possible sources of the discrepancy.

a. Develop a uniform probability model by assigning equal probability to all outcomes, and use the model to determine probabilities of events. [7-SP7a]
  • Example: If a student is selected at random from a class, find the probability that Jane will be selected and the probability that a girl will be selected.
b. Develop a probability model (that may not be uniform) by observing frequencies in data generated from a chance process. [7-SP7b]
  • Example: Find the approximate probability that a spinning penny will land heads up or that a tossed paper cup will land open-end down. Do the outcomes for the spinning penny appear to be equally likely based on the observed frequencies?

ACOS 2009 Correlation
Third Grade
  • 15 - Determine the likelihood of different outcomes in a simple experiment.
  • 15.1 - Defending predictions of outcomes of simple experiments.

Seventh Grade
  • 13.1 - Using a list, chart, picture, or tree diagram to represent outcomes.
  • 13.2 - Determining the number of possible outcomes using the Fundamental Counting Principle or other techniques.
Eighth Grade
  • 14 - Determine the theoretical probability of an event.
  • 14.3 Determining the probability of an event through simulation.

CMP2 Correlation
What Do You Expect

My Humble Opinion
This has moved down from 8th grade and has increased in rigor. Instead of students simply using a probability model, they are now being asked to develop a model. This is taught very thoroughly in the AMSTI unit What Do You Expect.