The STANDARD-DEVIATION function returns a numeric value that approximates the standard deviation of its arguments. The type of this function is numeric. 
 
  General Format
 
	  
	  
 
  Arguments
 
	   
	 - Argument-1 must be class numeric. 
	 
Returned Values
 
	   
	 - The returned value is the approximation of the standard deviation of the argument-1 series. 
	 
- The returned value is calculated as follows: 
		 
		  - The difference between each argument-1 value and the arithmetic mean of the argument-1 series is calculated and squared. 
		  
- The values obtained are added. This quantity is divided by the number of values in the argument-1 series. 
		  
- The square root of the quotient obtained is calculated. The returned value is the absolute value of this square root. 
		  
 
- If the argument-1 series consists of only one value, or if the argument-1 series consists of all variable occurrence data items and the total number of occurrences for all of them is one, the returned value is zero. 
	 
- Floating-point format is used for numeric non-integer results.