Why are many trials taken and averaged in an experiment?

Many trials are taken and averaged in an experiment to reduce the measurement error.  

A great manner by which error is reduced or to enhance the accuracy of measurement is to take many measurements and compute their average. In other terms, one attain accuracy via averaging.  

This also validates the repeatability of the measurement. The kinds of experimental error include mistakes in data entry, human error, mistakes in the design of the experiment, or systematic error, or random error due to environmental circumstances.  

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg 

which