SOLUTION: An island has 12 fur seal rookeries (breeding places). To estimate the fur seal pup population in Rookery A, 6861 fur seal pups were tagged in early August. In late August, a sampl

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Question 751049: An island has 12 fur seal rookeries (breeding places). To estimate the fur seal pup population in Rookery A, 6861 fur seal pups were tagged in early August. In late August, a sample of 600 pups was observed, and 219 of these were found to have been previously tagged. Use a proportion to estimate the total number of fur seal pups in Rookery A.
The estimated total number of fur seal pups in Rookery A is ____. (Round to the nearest whole number.)
Additional instructions: Set up a proportion, and then use the cross products principle of proportions. If a/b=c/d, then ad=bc. Be sure to round to the nearest whole number.
Answer by josgarithmetic(39838) About Me  (Show Source):
You can put this solution on YOUR website!
Late august----------- 600 observed : 219 tagged
Early august--------- p whole population : 6861 tagged

After the 6861 pups tagged in early august were released, they mixed uniformly with the whole seal population. The result of this mixing was as found in late august, but those 600 observed in late august gave a ratio which would be a strong estimate of the true ratio; no matter, we would setup the proportion using these ratios.
We want to find p, the whole population.
p%2F6861=600%2F219
p=6861%28600%2F219%29
p=18797
.
highlight%28p=18800%29 for best accuracy because we only have up to three significant figures.