Let $\displaystyle f(x)=\frac{3}{16}x^{2}$, $\displaystyle -c<x<c$

A. Find c so that f(x) is the p.d.f. of a random variable X.

B. Find $\displaystyle \mu$, $\displaystyle \sigma^{2}$ and $\displaystyle \sigma $

Could someone show me how to do this problem, or a problem similar to it? Thank you very much!