a mark/recapture study, an ecologist traps, marks, and releases 25 voles in a small woodland. A week late the trap is reset and she captures 30 voles. 10 of the 30 were marked. What is her estimate of the population?
2007-02-26 09:45:49 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Biology
75....? how did you get that? is there a formula or something?
2007-02-26 09:51:46 · update #1
to the guy who put 45...are you sure? that's what i thought too
i simply added 30 and 25 and subtracted 10.....seems too easy though?
2007-02-26 10:01:58 · update #2
It is 75.
25 voles were caught, marked and re-released. This number doesn't tell you anything yet, since we don't know how many voles there are total out in the environment.
A week later, 30 voles are captured. It's assumed that these 30 voles are randomly selected from the entire local vole population.
Ten of these 30 voles were ones that were marked in the previous trapping session. So the total vole population is equal to three times the number of marked voles (again, assuming that the voles are selected totally randomly).
We know how many voles were marked (25), so the total vole population is equal to three times the number of marked voles, which is 75.
2007-02-26 10:09:24 · answer #1 · answered by Anonymous · 1⤊ 0⤋
If the sample of 30 shows that 10 are marked, then that's saying 1 in 3 voles in the woodland is marked. Since we know that 25 were marked, then there's an estimated total of 75 voles.
2007-02-26 18:05:03 · answer #2 · answered by Scythian1950 7 · 1⤊ 0⤋
45
2007-02-26 17:57:17 · answer #3 · answered by Nano 1 · 0⤊ 1⤋
75? Don't quote me though.
2007-02-26 17:49:13 · answer #4 · answered by Anonymous · 1⤊ 0⤋
harty weinberg theorem
2007-02-26 17:56:55 · answer #5 · answered by Matt 2 · 0⤊ 1⤋