Using the gross requirements schedule below ${?}^{***},$ prepare an alternative ordering system that orders every $3$ weeks for $3$ weeks ahead $($a periodic order quantity$).$ What the cost of this ordering system?

$\backslash$table$[[$Period$,1,2,3,4,5,6,7,8,9,10],[$Gross requirements,$45,30,40,0,10,50,30,0,30,55]]$

$*$Holding cost $=$$$\frac{1}{?}$ unit$/$week; setup cost $=$$$150$; lead time $=1$ week; beginning inventory $=45$ units.

Prepare a net requirements plan $($enter your responses as whole numbers$).$

$\backslash$table$[[$Period$,,1,2,3,4,5,6,7,8,9,10],[$Gross requirements,,$45,30,$in$,\frac{?}{\text{b}\text{a}\text{r}}(0),10,50,30,0,30,55],[$On$-$hand at beginning of period,$45,,,,,,,,,,],[$On$-$hand at end of period,,,,,,,,,,,$],[$Net requirements,,,,,,,,,,,$],[$Order receipt,,,,,,,,,,,$],[$Order release,,,,,,,,,,,$]]$

The cost of this ordering system is $ $($enter your response as a whole number$).$