Typical seasonal index of the surf board
I started my own company manufacturing surf boards. For the last three years I recorded the following number of surf board sales for each quarter.
Year Winter Spring Summer Fall
2002 4 10 7 3
2003 5 12 9 4
2004 6 16 12 4
Determine a typical seasonal index for each of the four quarters.
The surf board business is definitely growing and in the spring of 2005 my sales totaled 15 boards for that quarter, but I have expected it because the typical seasonal index for that quarter is 1.668. The typical seasonal index for the fall quarter is .477. How many boards should I expect to sell in the fall of 2005?