how is the calculated z value. in "Consider an item with A$=$$$25$; D$=4000$units$/$year; v$=$$$8/$unit; L$=1$month; $($sign$)$L$=100$ units; TBS$=6$ months; and r$=0\mathrm{.}16$$$/$$$/$year$.$ A$.$ Compute the recorder quantity of the $($s$,$Q$)$policy using the EOQ B$.$ Compute the safety factor,SS$,$and recorder point. C$.$ Graph TBS versus ETVSPY$($the expected total value short per year$)"$ scenario