Excel STDEVA function

Function              STDEVA

Description        Excel STDEVA function returns the sample standard deviation of a supplied set of values.

Syntax  STDEVA(number1, [number2], …)

number1  First numerical value or reference in the sample.

number2  [optional] Second numerical value or reference in the sample.

Example:

=STDEVA(12,22,34,18)

Average of these 4 numbers is 21.5

=SQRT(((12-21.5)^2+(22-21.5)^2+(34-21.5)^2+(18-21.5)^2)/(4-1))=9.291573

Usage Note:

The Standard Deviation is a statistical measure, which is used to calculate the amount that a set of values deviate from the average or mean value.

When the data set is a sample of a large data set then instead of the Standard Deviation, Sample Standard Deviation is used. The equation for this is:

where,

x refer to each value in the set;

x̄ is the average (statistical mean) of the set of values;

n is the number of values.

Excel STDEVA function is very similar to Excel STDEV function. But there are some difference among them

• Logical values within arrays are ignored by STDEV function but it is counted (TRUE=1, FALSE=0) in STDEVA function.
• Text within arrays and reference arguments are ignored by STDEV function but it is counted 0 in STDEVA function.