Banana prices. The price of bananas fluctuates on the world market. Here are the prices ($/tonne) for the years 2000–2004. (Source: Holy See Country Review, 2008).

2000 2001 2002 2003 2004 422.27 584.70 527.61 375.19 524.84

a) Find a 3-year moving average prediction for the price in 2005.

b) Find a prediction for 2005 with an exponential smoothing model with

c) The actual price of bananas in 2005 was 577 $/tonne (you can find current prices at www.imf.org/external/np/
res/commod/table3.pdf.) Compute the absolute percentage error for each prediction.