4. ChocoTown has a 4,000 square foot outlet store that serves four major customer regions, denoted A, B, C and D. The locations of the points representing the customer regions and their weekly demands are shown in the table below. The ChocoTown outlet store is at location (10,20). Customer Demand Region Location ($/week) A (0,0) 4,000 B (0,20) 6,000 C (20,0) 4,000 D (40,20) 1,000 Candy Time is a new competitor of ChocoTown and they are considering opening a 4,000 square foot store at location (15,10). Assume the travel time from location i to j in minutes equals the straight line distance from i to j. (c) Suppose the Candy Time store is located at (15,10), but it is not 4,000 square feet. Use the spatial interaction model to find the size in square feet for the new CandyTime store that would allow it to capture a demand as close as possible to $9,000 per week. (d) Use the original size for the Candy Time store of 4,000 square feet. Use the spatial interaction model to find a location for the CandyTime store that would allow it to capture a demand as close as possible to $9,000 per week. What are the coordinates of this new location?