Statistics and Probability / Unequally Likely Outcomes

Understanding

Students recognize the difference between outcomes of a chance event that are equally likely and those that are not.

What to look for

By the end of this lesson, students should be able to use their experimental results and the theoretical probabilities to explain why the events in a chance process are or are not equally likely.

Sample Assessment

Are the outcomes in the spinner equally likely? Why or why not?

Answer: 
No, because the probability of getting each color is not the same: the probability of getting a red is (3/6), blue is (2/6) and green is (1/6).

The Big Idea

Not all outcomes of a chance event are equally likely.

What are the students doing?

Students experience setting up a model, using a simulation to collect data and estimate probabilities for a real situation in which the outcomes are not equally likely.

What is the teacher doing?

You may need to refer to Activity 13 in this series to refresh students on determining the probability of a compound event.