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.