Assume that it takes $(1)/(2)$ year to obtain the starter $$twigs$$ and plant a batch of trees, and another $2(1)/(2)$ years to grow the trees. How many trees should management consider a minimum level $($a reorder point$)$ that would trigger starting the cycle to grow a type of tree? In answering this question, assume that management wants to have a $90$ percent service probability while going through each planting cycle. Answer this question relative to the number of trees and years$-$of$-$supply for the trees.