Activity: Coincidence or Murder?
Today we are going to find out if Kristen Gilbert should be tried for murder.
Begin the activity by giving students 5 minutes to discuss whether or not they think Gilbert murdered her patients. They should use their activity pages from the beginning of the chapter. Then have a class discussion about what information they would like to have in order to decide if it’s murder or a coincidence. Guide them to the conclusion that they need information about how many deaths there were when Gilbert was working vs the number of deaths during shift when she was not working. Make sure to highlight that it is important that the shifts when she’s not working must be comparable, meaning the same time length, unit, floor, etc. Then give students the data they need and give them the rest of the time to work and come to a conclusion. They should use the four-step process. As you go through the results, point out which component most contributed to the test statistic. What does this tell us?
For more information on what happened next, check out this article.
This data could also be analyzed using a two proportion z test. You could have some students run that test as well to look for confirmation.