Sampling theory is the field of statistics that is involved
with the collection, analysis and interpretation of data gathered
from random samples of a population under study. The application
of sampling theory is concerned not only with the proper
selection of observations from the population that will
constitute the random sample; it also involves the use of
probability theory, along with prior knowledge about the
population parameters, to analyze the data from the random sample
and develop conclusions from the analysis. The normal
distribution, along with related probability distributions, is
most heavily utilized in developing the theoretical background
for sampling theory.