8.5.7 Let X be a random variable with E ( X ) = p,Var(X) = a' and such that the third central moment 7 3 = E ( X - p)3 exists. The ratio 73/a3 is called the coeficient of skewness. Find skewness of the following distributions: (i) U[O, 11. (ii)

f(x) = aza-' for 0 5 z 5 1 and f(z) = 0 otherwise (a > 1). (iii) BIN(1, p ) . (iv)

POI(X).