In 1984, the number of German marks required to buy one U.S. dollar was 1.80. In 1987, the U.S. dollar was worth 2.00 marks. In 1992, the dollar was worth 1.50 marks. In 1997, the dollar was again worth 1.80 marks.

a. What was the appreciation or depreciation of the dollar between 1984 and 1987? Between 1987 and 1992? Between 1992 and 1997?

b. What was the appreciation of the mark between 1984 and 1987? Between 1987 and 1992? Between 1992 and 1997?