In order to sign a purchase and sale contract with customers, Uncle Zhang estimated the total quality of fish in his own fish pond. He fished out 100 fish for the first time and weighed it as 186kg.

Therefore, the frequency of marked fish being fished out is 20200=0. 1,

There are 100 marked fish in the pond, so there are about100 ÷ 0.1=1000 fish in the pond.

Weight of fish in fish pond:

1000× 186+(4 18? 20× 1.86) 100+(200? 20)≈2024 (kg).

A: There are about 1000 fish in Uncle Zhang's fish pond, with an estimated weight of 2,024 Jin.