Sum of N Terms Of An Arithmetic Progression Definitions

Instructions: Use the following calculator as a series of examples. Perform the operation yourself and then check your answer by pressing the "=" key. If your answers do not match, check your work first. If you still do not understand refer to the definitions or incremental calculator page to review.
The following is the formula for calculating the Nth term of an arithmetic sequence of numbers.
n/2[2a+(n-1)d]

Enter your own values into the boxes or press new example for computer generated numbers.
To use as a quiz, try to evaluate the expression yourself and then check your answer. The calculator solves the following problem:
Find the sum of N terms of the arithmetic sequence which begins with a and changes with the addition or subtraction of d.
a =   n =   d =
Sn

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Chapter 5 Mathematics of Finance