Question

Environmental engineers studying a specific river wanted to estimate the population of bass in a certain area. In the first sampling they caught and marked 125 bass, in the second sampling, they also collected 125 more bass and found that only 14 of them had been originally marked.

1. What is the estimated bass population based on the findings of the two
samplings?

2. What would the population estimate be if they had caught 120 bass the second
time and only 8 of them had been originally marked from the original sampling?

3. What would the population estimate be if they had caught 50 bass the second
time and only 5 of them had been originally marked from the original sampling of
80?


4. What would the population estimate be if they had caught 130 bass the second
time and only 3 of them had been originally marked from an original sampling of
125?

5. What would the population estimate be if they had caught 40 bass the second
time and only 11 of them had been originally marked from an original sampling of
50?

ps - I am really confused. Please help

Answer 1

The formula used for estimation is:
Population = (total number captured) x (number marked) / (total captured with mark)

1.
Total capture = 125 + 125 = 250
Total marked = 125
Marked captures = 14
Population = (250 x 125) / 14
Population = 2,233 bass

2.
Population = (255 x 125) / 8
Population = 3,985

3.
Population = (130 x 80) / 5
Population = 2,080

4.
Population = (155 x 125) / 3
Population = 6,459

5.
Population = (90 x 50) / 11
Population = 410