6.5 The Wall Street Jour nal, on October 12, 2000, listed the following information on the exchange rates between the dollar and the German mark:

X0 = 2.2500 DM/$

E0 = $0.4444/DM XF (90 days) = 2.2399 DM/$

EF (90 days) = $0.4464/DM The U.S. prime rate on that day was 9.5 percent. What is the implied German interest rate?