ECO Auto Repair fixes about $1,300$ of a certain transmission part annually. ECO

purchases each part for $$55.$ They use $22\%$ annual interest rate for holding costs. The ordering cost $($or

setup cost$)$ for each order is estimated as $$33$ based on labor and shipping costs. Supplier lead time is $6$

weeks. Currently the company places an order to buy this transmission part once every $4$ months, but they

are not sure if this is optimal and would like you as a systems engineer to make a recommendation?