I have a homework question dealing with random walks. One part of the question required me to find the probabilities $p$ and $q$ such that
$$E[M_1] = M_0$$
which I achieved. Having found these, the next part requires me to use these values to find $E[M_{302}]$ given that $M_{300} = 60$. I'm not sure how to proceed with this.
EDIT:
$$M_n = \sum_{j=1}^N X_j$$