You have been charged with developing quarterly forecasts for overall demand for your company for the upcoming year. The company has been in business for quite some time, and thus there is a significantly large data set of historical demand with which to work. You have been instructed by your superiors that the data set likely contains trend, but company demand is not believed to be particularly seasonal. Also, the company went through a changeover in management at the end of the second year of the data, with impacts that are not necessarily known. The demand data are as follows: Period Year Quarter Demand 1 1 1 6846 2 1 2 7413 3 1 3 8097 4 1 4 7151 5 2 1 9047 6 2 2 7529 7 2 3 8207 8 2 4 9168 9 3 1 7609 10 3 2 7671 11 3 3 6196 12 3 4 6752 13 4 1 7119 14 4 2 6196 15 4 3 6282 16 4 4 5708 17 5 1 6314 18 5 2 5338 19 5 3 5360 20 5 4 5677 3 Some brief consulting with an outside expert revealed a few tips on how to attack