The Excel file: Graduation Party simulation.
What this Excel file does is simulates a student sending out 1500 invitations to a graduation party. There is a true proportion of people that will attend, but it is unknown (see the "Population" tab of the Excel spreadsheet is completely blacked and password protected). If you'd like the unlocked version, feel free to get in touch with me and I can send it along. Students will conduct samples of 20, 50, and 100 to estimate the true proportion, and once they've generated a sufficient number of each sample size, they'll take a guess as to what the true proportion is. Discussion follows as to which sample was most helpful to make the guess from. Most guesses are that the true proportion is between 0.2 and 0.3.
They choose one of their sample proportions for sample size 100 and create a confidence interval for 4 different confidence levels: 68%, 90%, 95%, 99.7% (not randomly thought up by any means). I chose these confidence levels because in the past I've seen students not associate confidence intervals with a middle percentage.
Collect students intervals using this form: One-Proportion Z-intervals Data Collection Form
Display their responses here: One-Proportion Z-Intervals Raw Data (pay attention to both tabs, one has intervals and one has whether or not the interval captures the true proportion)
Once they've done some thinking, they will open this Excel file(One-Proportion Z-intervals Displays of Each Interval), providing a visual of each confidence interval.
We follow with having students lead their own discussion. They'll begin by posting comments to a specific page of the class wiki, in order to get them to jot down an initial reaction to see if what they thought still holds up, or if their thinking needs revision. A whole class discussion follows, and I challenge them to not allow me to speak for 10 minutes. This can be difficult for me, but it is extremely difficult for them.