The nominal exchange rate is the rate at which one currency can be exchanged for another currency. In this case, we can calculate the nominal exchange rate between the US dollar and the Japanese yen as follows:
Nominal exchange rate = American car price / Japanese car price
Nominal exchange rate = $30,000 / 1,500,000 yen
Nominal exchange rate = 0.02 dollars/yen
Therefore, the nominal exchange rate between the US dollar and the Japanese yen is 0.02 dollars/yen.
The real exchange rate takes into account the relative purchasing power of the two currencies. To calculate the real exchange rate, we need to adjust the nominal exchange rate for the inflation rates in the two countries. Let's assume that the inflation rate in the US is 2% and the inflation rate in Japan is 1%.
Real exchange rate = Nominal exchange rate x (1 + inflation rate in US) / (1 + inflation rate in Japan)
Real exchange rate = 0.02 x (1 + 0.02) / (1 + 0.01)
Real exchange rate = 0.0196 dollars/yen
Therefore, the real exchange rate between the US dollar and the Japanese yen is 0.0196 dollars/yen. This means that the American car is relatively cheaper than the Japanese car in terms of purchasing power.