$19-15.($Applying interest rate parity$)$ On August $8,$ the six$-$month risk$-$free rate of interest in Switzerland is $4$ percent. If the spot exchange rate for dollars for Swiss francs is $0\mathrm{.}9252$ and the six$-$month forward exchange rate is $0\mathrm{.}9270,$ what do you expect the U$.$S$.$ six$-$month risk$-$free rate is$?$