Q1.The quarterly sales levels (measured in millions of dollars) for Goodyear Tiresare shown in the above Table.

A.Does there appear to be a significant seasonal effect in these sales levels? Plot the time series.

B.Perform the decomposition analysis using multiplicative & additive models .

C.Analyze this time series to get the four seasonal Indexes and interpret the indexes and determine the extent of the seasonal component in Goodyear's sales?

D.Forecastsales for the four quarters of 2007 for each model and compare the result& comment on them.

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Year Quartter Yt 2000 1 500 2 350 3 250 4 400 2001 5 450 6 350 7 200 8 300 2002 9 350 10 200 11 150 12 400 2003 13 550 14 350 15 250 16 550 2004 17 550 18 400 19 350 20 600 2005 21 750 22 500 23 400 24 650 2006 25 850 26 600 27 450 28 700