Question

Biologists want to know how many fish are in a certain lake. On January 1, they removed 600 fish from the lake and tagged them. On February 1, they returned to the lake and collected a random sample of 250 fish, of which 15 had been previously tagged. Approximately how many fish does the lake have, based on this experiment?

Answer 1

so we are assuming ratio and proporion


tagged:all=?:600

then we will assume a proportional sample

out of 250, 15 were tagged

so
250:15=?:600
250/15=?/600
50/3=?/600
times both sides by 600
30000/3=?
10000=?

10000 fish