An ecologist wanted to estimate population of species of fish in a pond. he immensed a net into the pond and collected 12 fish of this species.he marked them and released all of them back into the pond . after aweek he captured 25 fish of the same species . he found 4 marked fish among these 25 fish. assume that there is no population change during the period ,estimate the number of fish of that species in the pond.

Asked by richaverma914 | 27th Jun, 2015, 06:20: PM

Expert Answer:

L e t space t h e space t o t a l space n u m b e r space o f space t h i s space p a r t i c u l a r space s p e c i e s space o f space f i s h space b e space x. I t space i s space g i v e n space t h a t space h e space h a d space m a r k e d space 12 space f i s h space o u t space o f space t h e space e n t i r e space p o p u l a t i o n.  W h e n space h e space c a p t u r e d space 25 space f i s h space i n space t h e space n e x t space w e e k comma space h e space g o t space 4 space m a r k e d space f i s h. H e r e space w e space h a v e space t o space a s s u m e space space t h a t space t h e space r a t i o space r e m a i n s space c o n s tan t space t h r o u g h o u t space t h e space p o n d. 25 over x equals 4 over 12 therefore x equals 75.  T h e space a p p r o x i m a t e space n u m b e r space o f space f i s h e s space i n space t h e space p o n d space i s space 75.

Answered by Prasenjit Paul | 29th Jun, 2015, 10:33: AM