Find V(X)\displaystyle {V}{\left({X}\right)} if X\displaystyle {X} is a random variable with density function

f(x)=1161[0,16]\displaystyle {f{{\left({x}\right)}}}=\frac{{1}}{{16}}\cdot{1}_{{\text{[}{0}\text{,}{16}\text{]}}}

 
Give an exact answer, not a decimal approximation.