According to recent United Nations figures, the annual gun homicide rate is 62.4 per one million residents in the United States and 1.3 per one million residents in Britain.
a. Show how to compare the proportion of residents of the two countries killed annually by guns using the difference of proportions. Show how the results differ according to whether the United States or Britain is identified as Group 1.
b. Show how to compare the proportion of residents of the two countries using the relative risk. Show how the results differ according to whether the United States or Britain is identified as Group 1.
c. When both proportions are very close to 0, as in this example, which measure do you think is more useful for describing the strength of association? Why?