If Mrs. Jenkins is following this ratio precisely, there should be 6 bluegill fish in the pond for every 1 rock bass fish.
Let's break it down:
Mrs. Jenkins is putting in fish according to a ratio of 6 bluegill fish to 1 rock bass fish.
So, for every 6 bluegill fish she puts into the pond, she adds 1 rock bass fish.
If she only puts 1 rock bass fish into the pond, according to this ratio, she should be adding 6 bluegill fish alongside it.
Therefore, if Mrs. Jenkins is following this ratio precisely, there should be 6 bluegill fish in the pond for every 1 rock bass fish.