Scientists propose placing seismic stations on the fl oor of the Pacifi c Ocean to warn threatened coastal communities on the northwestern coast of the United States of approaching tidal waves caused by earthquakes. Since forewarned communities could take steps to evacuate, many of the injuries and deaths that would otherwise occur could be avoided if the government would implement this proposal.

The answer to which of the following questions would be most important in determining whether implementing the proposal would be likely to achieve the desired result?