Answer: The estimated number of robins in the population is 550
Step-by-step explanation: To estimate the population of robins, we will use the Mark-Recapture technique:
1) Capture a small number of individuals, mark them (with tags or other harmless identification) and release them;
2) After a period of time, catch another group and count the ones who have the mark;
3) Estimate the population using:
![N=\frac{M*C}{R}](https://tex.z-dn.net/?f=N%3D%5Cfrac%7BM%2AC%7D%7BR%7D)
where
N is the estimate of individuals in the population
M number of individuals marked
C is the total number of individuals captured the second time
R is the number of individuals with the mark recaptured
For the population of robins:
![N=\frac{55*300}{30}](https://tex.z-dn.net/?f=N%3D%5Cfrac%7B55%2A300%7D%7B30%7D)
![N=\frac{16500}{30}](https://tex.z-dn.net/?f=N%3D%5Cfrac%7B16500%7D%7B30%7D)
N = 550
<u>The best estimate for the robin population is </u><u>550</u>.