Calculate the share of energy received at the 4th trophic level, assuming that its total amount

Calculate the share of energy received at the 4th trophic level, assuming that its total amount at the 1st level was 1000 units.

1st trophic level: 1000 units;

2nd trophic level: 1000 units * 10% = 100 units;

3rd trophic level: 100 units * 10% = 10 units;

4th trophic level: 10 units * 10% = 1 unit.

If at the first trophic level there are 1000 units of energy, then at the fourth there is only one unit. This calculation is based on the ten percent rule for energy transfer to the food pyramid.