The ANNUITY function (annuity immediate) returns a numeric value that approximates the ratio of an annuity paid at the end of each period for the number of periods specified by argument-2 to an initial investment of one. Interest is earned at the rate specified by argument-1 and is applied at the end of the period, before the payment. The type of this function is numeric. 
 
  General Format
 
	  
	  
 
  Arguments
 
	   
	 - Argument-1 must be class numeric. 
	 
- The value of argument-1 must be greater than or equal to zero. 
	 
- Argument-2 must be a positive integer. 
	 
Returned Values
 
	   
	 - When the value of argument-1 is zero, the value of the function is the approximation of: 
		1 / argument-2 
		 
- When the value of argument-1 is not zero, the value of the function is the approximation of: 
		argument-1 / (1 - (1 + argument-1) ** (- argument-2)) 
		 
- Floating-point format is used for numeric non-integer results.