A $20-$year, $$zero$-$coupon bond was recently being quoted at $23\mathrm{.}983\%$ of par. Find the current yield and the promised yield of this$$ issue, given that the bond has a par value of $$$$1$ comma $000.$Then$,$ using semiannual$$ compounding, determine how much an investor would have to pay for this bond if it were priced to yield $11\mathrm{.}400\%.$