The incidence rates of Clostridium difficile are measured in both hospitals and nursing homes throughout a particular county. Those with low rates of infection were marked as having an effective nosocomial infection prevention strategy, while those with high rates were marked as having an ineffective strategy 
If the Department of Health Services wishes to determine whether hospitals or nursing homes have a more effective nosocomial infection prevention strategy, which of the following would be most appropriate?
Chi-squared test
One-way analysis of variance
Paired t-test
Pearson correlation