Population studies in biology and ecology often tag and release animals in order
ID: 3061663 • Letter: P
Question
Population studies in biology and ecology often tag and release animals in order to study the distribution, roaming habits, and other characteristics of the species. Suppose ten animals of a species thought near extinction in a region are caught, tagged, and released. After a long enough period of time for these ten to mix in with the rest of the population, a random sample of 15 of this species is caught. If there are actually 30 of these creatures in the population:
a) What is the probability that exactly 5 of the 15 animals captured the second time have tags?
b) What is the expected number of tagged animals in a sample of 15?
*Note: Solve without using Minitab or some other computer software, and detail every step of your answer.
Explanation / Answer
a) Probability = 10C5 * 20C10/30C15 = 0.3
b) Expected no of tagged animals = 0.3 * 15 = 4.5