You are the manager of a hospital emergency room. You are interested in analyzing the time patients wait to see a physician. For 25 samples of 5 patients each, the file P20_45.xlsx contains the time each patient had to wait before seeing a physician. Construct and interpret X and R charts for this situation. Also answer the following questions:

a. We are 68% sure that a patient will wait between what two values (in minutes) to see a physician?

b. We are 95% sure that a patient will wait between what two values (in minutes) to see a physician?

c. We are 99.7% sure that a patient will wait between what two values (in minutes) to see a physician?