Question:
A study conducted at the University of Chicago Hospitals compared the hospital related performance of “hospitalists”— physicians specializing in caring for hospitalized patients— to the performance of general internists who devote only a small percentage of their time caring for hospitalized patients. One of the variables examined was the average time that patients under the care of each of these two classes of physicians spent in the hospital. Patients in the sample who were cared for by internists stayed for an average of 4.59 days, while patients in the sample who were cared for by hospitalists left after an average stay of 4.1 days (uchospitals.edu). Construct a hypothesis test to test the null hypothesis that there would be no difference in the average hospital stay for the two populations represented here. Use a significance level of 1%. Assume the sample sizes were 488 for the internist patient sample and 162 for the hospitalist patient sample. Also assume that the population standard deviations are known: 1.5 days for the internist patient population and 1.4 days for the hospitalist patient population.