23. An emergency room physician implemented a study to determine if administering aspirin to heart attack victims immediately on arrival at the hospital reduced the proportion who subsequently died. Using data from a sample of 50 heart attack victims, the results of a test of significance caused the physician to conclude that administering aspirin did not change the proportion who subsequently died. Assuming the physician correctly implemented an appropriate, unbiased study design, what are the two possible explanations for this outcome? Which explanation do you think is more plausible? Explain