Abstract—In a one dimensional random walk of N steps, with a probability p of taking a step to the right, and a probability 1-p of taking a step to the left, it is not possible to determine from the ending position of the walk what N and p are. However, if the N-step random walk is repeated many times then a statistical analysis of the ending positions can be used to estimate both N and p. In this article we present the details of this analysis and test the results by Monte Carlo simulations. These simulations show that very accurate estimates of N and p are obtained even when the number of experimental trials is relatively small.

Index Terms—Sum from difference, two numbers, probability, random walk, simulation.

The authors are with Department of Mathematics and Physics, University of Wisconsin-Parkside, Kenosha, WI 53141, USA (email: mohazzab@uwp.edu).

Cite: Pirooz Mohazzabi, Thomas A. Fournelle, "Finding the Sum of Two Numbers from Their Difference," International Journal of Applied Physics and Mathematics vol. 7, no. 3, pp. 209-215, 2017.