Research suggests that chest-compression-only (CC) may be more effective than standard cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (Cabrini et al, 2010). A meta-analysis by the authors found that, of the 1842 cases where CC instructions had been given, 211 patients survived and that, of the 1895 cases where CPR instructions had been given, 178 patients survived.

This situation calls for inference for the difference between two population proportions, which is not a topic that we discussed this term. Even so, in this question, we will extend our knowledge to this scenario.

As you might expect, the point estimate for the difference in survival rates of patients who received CC for out-of-hospital cardiac arrest and patients who received CPR treatment for out-of-hospital cardiac arrest is the difference between the sample proportions. As a reminder, a meta-analysis by the authors found that, of the 1842 cases where CC instructions had been given, 211 patients survived and that, of the 1895 cases where CPR instructions had been given, 178 patients survived. What is the value of the point estimate?