Examine the following quarterly data:

t 1 2 3 4 5 6 7 8 9 10 11 12 yt 2 12 23 20 18 32 48 41 35 52 79 63

a. Compute the four-period moving averages for this set of data.

b. Compute the centered moving averages from the moving averages of part a.

c. Compute the ratio-to-moving-averages values.

d. Calculate the seasonal indexes. Normalize them if necessary.

e. Deseasonalize the time series.

f. Produce the trend line using the deseasonalized data.
g. Produce seasonally adjusted forecasts for each of the time periods 13, 14, 15, and 16.