Use the tagging and recapturing technique to estimate the number of fish in a pond. Suppose 140 fish
were captured, tagged, and released. Then 50 fish were recaptured and among them 20 were found to be
tagged. Estimate the number of fish in the lake.
20/50 = 140/x
Solve for x.
750
To estimate the number of fish in the pond using the tagging and recapturing technique, we can set up a proportion based on the number of tagged fish recaptured.
Let's say the total number of fish in the pond is represented by 'N'. We know that 140 fish were initially tagged and released, and then 50 fish were recaptured, with 20 of them being tagged.
The proportion we can set up is:
(Tagged fish recaptured) / (Total fish initially tagged and released) = (Total fish recaptured) / (Total fish in the pond)
So, we can write the proportion as:
20 / 140 = 50 / N
To solve for 'N', we can cross-multiply and solve for it:
20N = 140 * 50
20N = 7000
N = 7000 / 20
N = 350
Therefore, the estimated number of fish in the pond is 350.