$(20$ points$)$ Zi corp. has obtained the financing by issuing bonds and stocks. It has just issued $50,000$ zero$-$coupon bonds with $3$ years of maturity. Each bond has the face value of $$1,000$ and sells at $$849\mathrm{.}2$ now. Zi has issued $1$ million of common stocks and each stock sells at $$38$ now with a beta of $1\mathrm{.}1.$ The market risk premium is $7\%$ and the risk$-$free rate is $4\%$ per annum. It has also issued $150,000$ preferred stocks. Each preferred stock pays $$2$ at the end of every year and sells at $$16$ now. With tax rate of $21\%,$what is the weighted average cost of capital for Zi corp.?