A random sample of 13 observations from a population yielded $\displaystyle \sum$ x=488.8 and $\displaystyle \sum$ $\displaystyle x^2$ = 18950.2. Estimate $\displaystyle \mu$ and $\displaystyle \sigma.$

I can't find this in my notes, I think $\displaystyle \sum$ x = 488.8 would be the sum of the sample, not sure where to go from there.

Thank you