A company faces the following demand during the next 3 weeks: week 1, 20 units; week 2, 10 units; week 3, 15 units. The unit production costs during each week are as follows: week 1, $13; week 2, $14; week 3, $15. A holding cost of $2 per unit is assessed for units in ending inventory each week. At the beginning of week 1, the company has 5 units on hand. Determine how to minimize the cost of meeting demand for the next 3 weeks. (The optimal cost should be $560.) After solving the problem, use the SolverTable to see what happens to the decision variables and the total cost when the initial inventory varies from 0 to 30 in increments of 5 units. How much lower would the total net cost be? and at what rate of decrease?