Question

How many units of energy would there need to be in the first trophic level to end up with 1000 units of energy in the second? in the third? in the fourth?

Answer 1

(First) 10,000--->1000--->100-->10 (fourth)

Step-by-step explanation:

Each trophic levels gets reduced by factor of 10.

Thus if you start with 10,000 in first, then you end with 1000 in second, 100 in third and 10 in forth.