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.