On the asymptotic and approximate distributions of the product of an inverse Wishart matrix and a Gaussian vector
Keywords:
Wishart distribution, multivariate normal distribution, integral approximationAbstract
In this paper we study the distribution of the product of an inverse
Wishart random matrix and a Gaussian random vector. We derive its asymptotic
distribution as well as its approximate density function formula which is based on the
Gaussian integral and the third order Taylor expansion. Furthermore, we compare
obtained asymptotic and approximate density functions with the exact density which
is obtained by Bodnar and Okhrin (2011). A good performance of obtained results
is documented in the numerical study.