The O(alpha^2 mt^2/mw^2) correction to the relation between G_\mu and the
vector boson masses is computed in the MSbar scheme, and the results are used
to investigate the magnitude of the effect on the theoretical prediction of mw
and sin^2\theta_\msbar(mz) from alpha, G_\mu, and mz.Comment: 11 pages, LaTeX, includes 1 LaTeX figure, uses equations.sty and
cite.sty, one minor comment and interpolation function for variable mtop
added, no change in the result
