11.25 The waiting time (in minutes) for emergency room patients with non-life-threatening injuries ...

     11.25 The waiting time (in minutes) for emergency room   patients with non-life-threatening injuries was measured at four hospitals   for all patients who arrived between 6:00 and 6:30 PM on a certain Wednesday.   The results are shown below. Research question: Are the mean waiting times   the same for emergency patients in these four hospitals?           Emergency   Room Waiting Time (minutes)    Hospital   A Hospital B Hospital C Hospital D    (5   patients) (4 patients) (7 patients) (6 patients)    10 8 5 0        19   25 11 20       5 17 24 9        26 36 16 5        11 18 10        29 12        15