TireXR has plants at Node 1 and Node 2 producing tires at weekly rates of 2500 units and 3500 units respectively. The units are transported to one of the two warehouses at Node 3 and Node 4, and then to retailers at Node 5, Node 6 and Node 7. The transport costs per unit (in dollars) and demands of the retailers are shown below. Node 3 4 1 5 4.2 2 5.5 4.5 Node = 5 demand = 1250 9.2 7.2 6 demand = 1500 8.5 8 7 demand = 2000 6.2 5.2 3 4 The objective is to find the cheapest transport scheme. Let Xij be the number of units to be transported from Node i to Node j. Solve the LP problem using Excel and answer the following questions on Moodle. Question 1.1: Fill in the boxes in the partial Excel spreadsheet (provided in Moodle). Question 1.2: Find the optimal transport scheme. Question 1.3: Find the minimum total transport cost. Question 1.4: If the unit transport cost from Node 4 to Node 6 is to decrease, what is the lowest cost it can decrease to without changing the optimal transport scheme? Question 1.5: If the unit transport costs from the Node 1 to the warehouses are all decreased by 1.5 dollars, what is the total percentage change? Find the minimum total cost. Question 1.6: If the demands of the three retailers are each decreased by 150 units, what is the total percentage change? Find the change in minimum total cost