A recent study of health service costs for coronary angioplasty versus coronary artery bypass surgery at a London hospital (The Lancet, October 1, 1994, page 929) showed an average cost of £6176 with a standard deviation of £329 for 231 angioplasties and an average cost of £8164 with a standard deviation of £264 for 221 bypass surgeries. Is this sufficient evidence to say that the average cost of angioplasty is less than the average cost of bypass surgery?
(A) P < .001, so this is very strong evidence that angioplasty costs less.
(B) P is between .001 and .01, so this is strong evidence that angioplasty costs less.
(C) P is between .01 and .05, so this is moderate evidence that angioplasty costs less.
(D) P is between .05 and .10, so there is some evidence that angioplasty costs less.
(E) P > .10, so there is little evidence that angioplasty costs less.
Answer: A