Discussion:
Awson and Jick [1976] compare drug prescription in the United States and Scotland.
In patients with congestive heart failure, two or more drugs were prescribed in 257 of 437 U.S. patients. In Scotland, 39 of 179 patients had two or more drugs prescribed. Test the null hypothesis of equal proportions giving the resulting p- value. Construct a 95% confidence interval for the difference in proportions.