Recall that demand for the bird feeder is normally distributed with a mean of $18$ units per week and a standard deviation in weekly demand of $5$ units. The lead time is $2$ weeks, and the business operates $52$ weeks per year. The Q system where reorder point is used, the lot size for each order is $75$ units. what is the equivalent p system if management still wants $90$ percent cycle service level? in other words, what are the time between p and target inventory level t$?$