Hospital losses. Table 27.6 gives data on the losses (in dollars) incurred by a hospital in treating major joint replacement (DRG 209) patients.13 The hospital has taken from its records a random sample of 8 such patients each month for 15 months.
(a) Make an s control chart using center lines and limits calculated from these past data. There are no points out of control.
(b) Because the s chart is in control, base the 
chart on all 15 samples. Make this chart. Is it also in control?
