Today’s Wall Street Journal (May 12, 2016) has an article that you can turn into a teaching exercise, on a topic your students will all have opinions about, namely airline travel award redemption. Of the 25 airlines studied, the Journal found a wide discrepancy in ease of booking a coach seat using frequent flyer miles.
Best among the US carriers: Southwest, which had award seats available for 100% of queries, and Jet Blue, which offered seats 92.9% of the time. Among the worst US carriers: American, which did not have seats for 43.6% of requests.
The overall average of 76.6% (which was better than I expected) for the carriers shown can be used as the center line in a p-bar chart. Using Excel, Excel OM, or POM for Windows, your students can compute 3-sigma upper and lower limits and draw conclusions about which carriers are “out of control.”
This should lead to a nice discussion about service quality (Ch.6).