10.137 [EX10-137] The amount of general anesthetic a patient should receive prior to surgery has received considerable public attention. According to the American Society of Anesthesiologists, every year, about 40,000 (some researchers have put the figure closer to 200,000) of the 28 million patients who undergo general anesthesia experience limited awareness during surgery because of resistance to the medication or from too little dosage. Patients commonly report overhearing doctors conversing with nurses and assistants during operations.

Source: People, “Wake-Up Call”

Suppose a study is conducted using 20 patients who are having eye surgery performed on both eyes, with 2 weeks separating the treatments on each eye. Ten of the patients are given a lighter dose of general anesthetic prior to surgery on the first eye, and the other ten patients are given a heavier dose. The following week, the procedure is reversed. Two days after each surgery is performed, the patients are asked to rate the amount of pain and discomfort they experienced on a scale from 0 (none) to 10 (unbearable). Results follow:

Subject Light Dosage Heavy Dosage Subject Light Dosage Heavy Dosage 1 4 3 11 6 7 2 6 5 12 7 5 3 5 6 13 10 7 4 8 4 14 3 2 5 4 5 15 1 0 6 9 6 16 5 6 7 3 2 17 6 3 8 7 8 18 8 5 9 8 5 19 4 2 10 9 7 20 2 0 Can you conclude that the heavier dose of anesthetic resulted in the patients experiencing lower pain and discomfort after the eye surgery? Use the 0.01 level of significance.

a. Solve using the p-value approach.

b. Solve using the classical approach.