2. Recall from Chapter 6 that the Big Mac index is used as a rough measure of purchasing power parity across countries. In January 2021, The Economist magazine reported: “A Big Mac costs 66,000 dong in Vietnam and US$5.66 in the United States. The implied exchange rate is 11,660.78. The difference between this and the actual exchange rate, 23,064.00, suggests the Vietnamese dong is 49.4% undervalued.” What The Economist refers to as the implied exchange rate is the hypothetical exchange rate that would make the real exchange rate 1. The actual exchange rate was 23,064.00 dong per U.S. dollar. Explain why this analysis led The Economist to suggest that “the Vietnamese dong is 49.4% undervalued.”3