Let $\psi^2$ be a non-central chi-square distribution with parameters (N, p). Let $\delta = \sqrt{(T*\psi^2-N)/(T\psi^2)}.$ 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 [email protected]. Thanks.