Answer: The estimated number of robins in the population is 550
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=(M*C)/(R)](https://img.qammunity.org/2021/formulas/mathematics/high-school/6ly8bn37u1894jcrgfhectluvbb4x5739a.png)
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=(55*300)/(30)](https://img.qammunity.org/2021/formulas/mathematics/high-school/qbf0jeiid5rz30hxj725w5gbgmhywca4he.png)
![N=(16500)/(30)](https://img.qammunity.org/2021/formulas/mathematics/high-school/c5r871gsxj3l2m19oweh0k2jb8na5p8e22.png)
N = 550
The best estimate for the robin population is 550.