1. Find a journal article that uses a Fisher's exact test to test for independence of two categorical variables (in a contingency table).
   1. Why did they use this test instead of the chi-squared test?
   2. Write the reference to the article,
   3. copy the contingency table into your homework, and
   4. reproduce their p-value (show the STATA output).
   5. What conclusion did the investigators draw? Did they use the correct statistical test? If not, did they come to the right conclusion?