The trend equation y^ = 150 + 12x + 0.01x2 has been developed for annual unit sales of a filtering system component used by municipal water authorities.
The years have been coded so that 1996 corresponds to x = 1. If the seasonal indexes for quarters I through IV are 85.0, 110.0, 125.0, and 80.0, respectively, estimate the unit sales for each quarter of 2010.