Question 832076
The actual fraction of tagged trout is 125/p, using p = trout population of the lake.


The later sampling of 112, containing 62 tagged trout gives you a ratio which is very close-to the 125/p ratio.


{{{125/p=62/112}}}
{{{p/125=112/62}}}
{{{p=125*112/62}}}
{{{p = 225}}}  or {{{p=226}}} trout.