In problem $3,$ the setup team has set the target production lot size to five units. The production rate on the machine is $40$ units$/$hour$,$ the demand for the part is $10$ units$/$hour$,$ and the carrying cost of the part is $$4\mathrm{.}25$ per unit per year. Assume annual demand is $8000$ units. What must the setup time be reduced to for this part? $($Hint: Look at EMQ in Chapter $5,$ Small Lot Production.$)$