Let $psi^2$ be a non-central chi-square distribution with parameters (N, p). Let $delta = sqrt{(T*psi^2-N)/(Tpsi^2)}.$ Calculate the mean and variance of $delta.$ (Notice that $T*psi^2 -N$ can take negative values. Hence the thing in the sqrt is the positive part of it). N and T are positive integers, and p is a positive real number. If interested, please contact me at busom77@yahoo.com. Thanks.