Let X be a continuous random variable with density fx(s) = k(s$^{-6}$) for s $\ge$ 1 and fx(s) = 0 for s<1.
1.) Determine the value of the constant k.
2.) Calculate E(X), VAR(X)
3.) Calculate P(X $\in$ [-2,-0.75])
I know I must integrate with respect to s and for E(X) = (X$^2$-E(X)) and VAR(X) = (X-E(X))$^2$, but how can I format it correctly to find E(X), VAR(X), k, and P(X $\in$ [-2,-0.75]) ?