Two unknowns, two moments for a normal fit

You model the size of a bid-ask spread (in ticks) as a normal distribution with unknown mean $\mu$ and unknown variance $\sigma^2$. From a large sample you compute the average $\frac{1}{n}\sum X_i = 2$ and the average of the squares $\frac{1}{n}\sum X_i^2 = 13$.

Use the method of moments to estimate $\mu$ and $\sigma^2$.