The document describes three capture-recapture experiments used to estimate population sizes: 1) 213 salmon were marked and released in a lake, later 104 were captured including 13 marked, estimating the salmon population. 2) A survey of 40 high school students out of 200 people estimates the town population. 3) Observers saw 48 taxicabs one day and 52 the next in Edinburgh, with 10 seen both days, allowing an estimate of the total taxicab population.

1. Metodo cattura e ricattura
1. Al Dryden Lake in New York, alcuni ricercatori,
marcano, e rilasciano 213 salmoni. Più tardi catturano
104 salmoni e trovano che 13 sono marcati. Stima il
numero di salmoni in Dryden Lake.
2. Suppose that the high school in a town has 500
students. A random survey of 200 people in the
town finds 40 high school students. What is the
estimate for the number of people in the town?
3. Visitors conducted a capture-recapture experiment to
determine the number of taxicabs in Edinburgh,
Scotland. On the first day, observers saw 48
taxicabs. The next day they observed 52 cabs, 10
of which they had seen the previous day. What is the
estimate for the number of taxicabs in Edinburgh?
Thanks to:
http://www.horton.ednet.ns.ca/staff/wheadon/index.htm