Question: Kaiser Medical compares the length of hospital stay for a random sample of 40 patients in New York with that for a similar sample of 30 patients in Detroit. Do the data indicate a difference in the mean lengths of a hospital stay in the 2 cities?

a. State in symbolic form the appropriate null and alternate hypotheses.

b. At the 90% level of significance, what is the decision rule?

c. The mean length of stay is 5.21 days in New York, with a standard deviation of 2.3 days. The Detroit average is 4.65 days, with a sample standard deviation of 1.9 days. What do you conclude? State your findings in a sentence.