There have been reports that animals can smell cancer and other diseases. According to the British Broadcasting Corporation (2015, October) a lady in the United Kingdom named Joyce stated that she smelled a "subtle musky odor" on her husband Les that she had never smelled before. At first, Joy thought maybe it was just from the sweat after long hours of work. But when Les was diagnosed with Parkinson's 6 years later, Joyce suspected the odor might be a result of the disease.

Scientists were intrigued by Joyce's claim and designed an experiment to test her ability to "smell Parkinson's". Joy was presented with 12 different shirts, each worn by a different person, some of whom had Parkinson's and some of whom did not. The shirts were given to Joyce in a random order and she had to decide whether each shirt was won by a Parkinson's patient or not.

1. Why would it be important to know that someone can smell Parkinson's disease?
2. At what confidence level would you feel comfortable in stating that Joyce was able to "smell Parkinson's" and wasn't just guessing?
3. Do you feel a sample of 12 shirts is a larger enough sample?