Every Year, the Veterinary Hospital at a Major Research University

Multiple Choice

Every year, the veterinary hospital at a major research university treats a number of horses that have stones called enteroliths in their guts. A sample of 20 years shows that, on average, about 2% of horses presenting at the veterinary hospital are treated for enteroliths. In the long run, the probability that a horse arriving at the veterinary hospital has enteroliths is:

A) 0.05.
B) 0.02.
C) 0.5.
D) The answer cannot be determined from the information given.