This study analyzes validity of the relative purchasing power parity (PPP) and the uncovered interest rate parity (IRP) theories for the dollar/euro exchange rate. The period of analysis is from 1990 to 2003. The dollar/euro exchange rate represents the currencies of a country, the USA, and a region, the Euro Area. The basic data needed for this study are the dollar/euro exchange rate, and the inflation and the interest rates for the USA and the Euro Area. Since the Euro Area was officially formed on January 1st, 1999, we had difficulty in finding the data for the Euro Area. For the lacking Euro Area data, synthetic values are created by using the individual data of Euro Area countries. These synthetic values are treated as the equivalents of the actual values and are used in the parity implied dollar/euro exchange rate calculations. The parity implied dollar/euro exchange rates are compared with the actual dollar/euro exchange rates. Our results indicate that the parity implied dollar/euro exchange rates are statistically significantly different from the actual dollar/euro exchange rates. In other words, both the PPP and the IRP theories do not hold for the dollar/euro exchange rate.