Enterprise industries produces Fresh, a brand of liquid laundry detergent. In order to manage its inventory more effectively and make revenue projections, the company would like to better predict demand for Fresh. To develop a prediction model, the company has gathered data concerning demand for Fresh over the last $30$ sales periods $($each sales period is defined to be a four$-$week period$).$ The demand data are presented in Lapicture Excel Data File. For each sales period, let

X$1=$

X$2$

XB

$=$

the demand for the large