A type of continuous distribution with a finite range, which models the outcomes of a system involving $n$ independent variables, each with a uniform distribution, i.e. the distribution of $X=\sum _{k=1}^n{U}_k$. The Irwin Hall Distribution is defined only by the value of $n$. If $n=1$, the distribution is uniform; $n=2$ yields a triangular distribution; and for $n$ values above that the result approaches the normal distribution in appearance.