$($d$)$ Use a multiple regression model to develop an equation to account for trend and seasonal effects in the data. Use the dummy

variables you developed in part $($b$)$ to capture seasonal effects and create a variable $t$ such that $t=1$ for Quarter $1$ in Year $1,$

$t=2$ for Quarter $2$ in Year $1,$dotst$=12$ for Quarter $4$ in Year $3.$

If required, round your answers to three decimal places. For subtractive or negative numbers use a minus sign even if there

is a $+$ sign before the blank $($Example: $-300).$

hat$(y)=,Qtr1+,Qtr2+Qtr3+,t$