Use the tagging and rectapturing technique to estimate the number of fish in a pond?
suppose 140 fish were captured, tagged, and released. Then 50 fish were recatured and and among them 20 were found to be tagged. Estimate the number of fish in the lake.
- Jim BurnellLv 61 decade agoFavorite Answer
If the 50 fish that you recaptured were a good sample that represented the actual distribution of tagged fish to untagged fish, then you could guess that 20/50 = 40% of the fish in the pool had been tagged. Therefore, since you know you tagged 140 of them, there must be about 140/.4 = 350 fish in the pond.
It all depends on how good your sample was.
I'm not much of a statistics expert, so I don't know if there's a good way to guess how well your sample matches the actual distribution of fish, but just thinking about it, that's my guess.
- 1 decade ago
That sounds about right.