Statistics: Density Function

Hi just having a bit of trouble with the following question, any help would be appreciated, thanks.

Let $2500^{-1} x^3$ be a density function on $[0,10]$. What is the value of $Sd(x)$?

All you have to do is calculate $E(X)$ and $E(X^2)$ using the proper integrals. By finding these,you get to know about $Var(X)$ . Then $SD(X) =sqrt (VarX)$