What are the observational units?

A legendary story on college campuses concerns two students who miss a chemistry exam because of excessive partying but blame their absence on a flat tire. The professor allows them to take a make-up exam, and sends them to separate rooms to take it. The first question, worth 5 points, is quite easy. The second question, worth 95 points, asks: Which tire was it? 

STEP 1: Ask a research question. Do students pick which tire went flat in equal proportions? It has been conjectured that when students are asked this question and forced to give an answer (left front, left rear, right front, or right rear) off the top of their head, they tend to answer “right front” more than would be expected by random chance. 

STEP 2: Design a study and collect data. To test this conjecture about the right front tire, a recent class of 28 students was asked, if they were in this situation, which tire would they say had gone flat. We obtained the following results:  

Transcribed Image Text:

Left front 6 Left rear 4 Right front 14 Right rear 4