Statistics and Probability / What is Probability

Understanding

Students will recognize that the probability of an outcome can be estimated from the long-run relative frequencies.

What to look for

Students should notice that the more repetitions of an experiment leads to an relative frequency that is closer to the theoretical probability.

Sample Assessment

Identify each as true or false:

a. The probability of an outcome can be 2/1.
b. The probability of an outcome can be 0. 
c. If an outcome is sure to happen, the probability of the outcome is 1.

Responses:
a. False
b. True
c. True

The Big Idea

Probability, which is the value assigned to the likelihood of an event occurring, can take on any numerical value between and including 0 and 1. The higher the probability, the more likely the event is to occur.

What are the students doing?

Students explore how they can use probability to help choose a winning outcome.

What is the teacher doing?

Be sure students explain how they know which outcome is more likely in each of the simulations and how they might describe the probability of each.