A study investigated survival rates for in-hospital patients who suffered cardiac arrest. Among 58,593 patients who had cardiac arrest during the day, 11,604 survived and were discharged. Among 28,155 patients who suffered cardiac arrest at night, 4139 survived and were discharged (Journal of the American Medical Association). We want to use a 0.01 signicance level to test the claim that the survival rates are the same for day and night. (a) State null and alternative hypotheses.

(b) Compute the test statistic.

(c) Calculate critical values.

(d) Construct an appropriate condence interval.

(e) Does it appear that for in-hospital patients who suffer cardiac arrest, the survival rate is the same for day and night?