n 
Sample Size 
N 
Population Size 
x 
The value of the sampling unit that is being used as the primary
variable of interest. In audit sampling, this would be the audited
(or revised) value of the transaction.

y 
The value of the sampling unit that is being used as the “paired”
variable that is related to the variable of interest. In audit sampling,
this would be the reported (or original) value of the transaction.

d 
The value of the sampling unit that is the difference between
“paired” variable (y) and the variable of interest (x).
That is, d = x  y. In audit sampling, this would be the difference
(or the change) of each transaction’s value.

X 
The total value of the primary variable of interest. In audit
sampling, this would be the estimated total audited value of the population.
Typically, this value is not known for the entire population and
is estimated based on the statistical sample selected.

Y 
The total value of the variable that is paired with variable
of interest. In audit sampling, this would be the total reported
value of the population. Typically, this value is known for the entire
population and may be estimated based on the statistical sample selected.

D 
The total value of the difference between the “paired”
variable and the variable of interest. In audit sampling, this would
be the estimated total difference of the population. Typically, this
value is not known for the entire population and is estimated based
on the statistical sample selected.

U_{R} 
The confidence coefficient which is based on either the Student’s
tdistribution or the normal distribution. For example, a 95% onesided
confidence coefficient based on the normal distribution is 1.645.
This term is often referred to as the tvalue and the zvalue.
