$($Interest rate determination$)$ If the$10-$year Treasury bond rate is $5\mathrm{.}9\%5\mathrm{.}9\%,$ the inflation premium is $1\mathrm{.}5\%1\mathrm{.}5\%,$ and the$$ maturity$-$risk premium on$10-$year Treasury bonds is $0\mathrm{.}7\%0\mathrm{.}7\%,$ assuming that there is no$$ liquidity$-$risk premium on these$$ bonds, what is the real$$ risk$-$free interest$$ rate?