SOLUTION: To determine the number of trout in a lake, a conservationist, catches 129 trout, tags them, and releases them. Later 191 trout are caught, and it is found that 55 of them are tagg

Algebra ->  Probability-and-statistics -> SOLUTION: To determine the number of trout in a lake, a conservationist, catches 129 trout, tags them, and releases them. Later 191 trout are caught, and it is found that 55 of them are tagg      Log On


   



Question 1161876: To determine the number of trout in a lake, a conservationist, catches 129 trout, tags them, and releases them. Later 191 trout are caught, and it is found that 55 of them are tagged. Estimate how many trout there are in the lake.
The estimated number of trout is approximately ___. (Round to the nearest integer.) Tutor, I keep getting the wrong answer. This is what I did.
Let x= the estimated number of trout in the lake.
x trout/129 tagged trout = 191 trout/55 tagged.
Next, I simplified by cross-multiplication. x*55 = 129*191.
Next, to get the variable x alone, divide both sides by 55. x=129(191)/55 = 9,550/50 = x=191. Tutor x=191 is wrong.

Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
p trout in the lake
129 trout removed, tagged, put back

129%2Fp=55%2F191
p%2F129=191%2F55
p=%28191%2F55%29129
highlight%28p=448%29

Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.

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    - Using proportions to estimate the number of fish in a lake
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