Excel STDEV.P function

Function              STDEV.P

Description        Excel STDEV.P function returns the standard deviation of a supplied set of values.

Syntax  STDEV.P(number1, [number2], …)

number1  First numerical value or reference in the set.

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

Example:

=STDEV.P(12,22,34,18)= 8.046738

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)=8.046738

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.

The Standard Deviation equation 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.