Overall Notes

• There is one version of this assessment provided in the Teacher Resources Materials (TRM). Use this assessment as-is or use it as a model to create your own. 

• If you are making your own assessment, consider using the test bank and the ExamView software.

​

Note for This Quiz

• During the quiz, we allowed students to use the “Counting Methods” applet to find combinations and the  “Binomial Distributions” applet to find probabilities. When we wanted students to do something by hand on the quiz, it was clearly indicated (Using the binomial formula, find the probability of exactly 3 successes). Otherwise, they could use the applets to help them, or check their answers. 

​

Common Student Errors

• Students sometimes want to simply write “BINS” with four checkmarks when checking conditions for a binomial distribution. We suggest requiring students to write out enough to demonstrate that they know each condition and how to check it. 

• Students sometimes think that if there are more than two possible outcomes (5 color Skittles), the “Binary” condition cannot be satisfied. This can be remedied by creatively defining the two possible outcomes, like “green” and “not green”. 

• When using the binomial formula, students sometimes forget to include the combination at the front of the calculation. Help them to realize that there are many ways of obtaining r success in n trials and we need to account for this. 

• When calculating binomial probabilities, students often struggle with choosing the right boundary value. For example “less than 3” is P(X<3) while “at most 3” is P(X<=3). Be sure students understand the meaning of “at least”, “at most”, “more than”, and “less than”. 

• When students are using a normal approximation to a binomial, they often forget to justify why they can do this using the Large Counts condition.