The Quarterly Sales of a Company (In Millions of Dollars)

Essay

The quarterly sales of a company (in millions of dollars) over the past three years are given in the following table.
a.Compute the four seasonal factors (Seasonal Indexes). Show all of your computations.
b.The trend for these data is Trend = 20.82 + 0.336 t (t represents time, where t=1 for Quarter 1 of 2007 and t=12 for Quarter 4 of 2009). Forecast sales for the first quarter of 2010 using the trend only. Show all of your computations.
c.Forecast sales for the first quarter of 2010 using the trend and seasonal indexes and write your answer below. Show all of your computations.