2. Population Distributions
a. For audit purposes, each item in a population is associated with a variable of interest to the auditor.
1) Discrete variables, such as the yes/no decision whether to authorize payments of invoices, are tested using attribute sampling (this is discussed in further detail in Subunit 6.3).
2) Continuous variables, such as the monetary amount of accounts receivable, are tested using variables sampling (this is discussed in further detail in Subunit 6.4)
b. An importance characteristic of a population is the distribution of the values of the variable of interest.
1) Of the many types of distributions, the most important is the normal distribution (the bell curve), depicted in Figure 6-1 below. Its values form a symmetrical bell-shaped curve centered around the mean.