Summary I'm trying to calculate $Var(X^t)$ where $t$ is the number of periods using only the following known parameters:
$E(X)$ and $Var(X)$. $X$ is a random variable and is the return factor $(1 + r)$ where $r$ is normally distributed with finite, non-zero mean and variance.
Background I'm attempting to determine the parameters of a probability distribution of the ending dollar value of an investment portfolio assuming that each time period's returns are normally distributed with a known mean and known variance.
To determine the ending distribution, I need the variance of the compounded returns at the ending period. The ending expected value is easy to calculate, but the ending variance is determined indirectly by higher moments which are not directly known without using more exotic methods.
An approximation of the variance of compounded return factors at any time $t$ can be observed through a Monte Carlo simulation, however these estimates are noisy without running large numbers of trials and are not feasible for my particular application.