1. Transportation of Hard Disk Drives. A hard disk drive (HDD) manufacturer is loo- king to solve a logistics problem for its North American market. The HDD manufacturer has 3 production centres in Sunnyvale (California), Dublin (Ireland) and Bangkok (Thai- land) respectively. The manufacturer serves its North American demand of HDD through 4 warehouses in Amarillo (Texas), Teaneck (New Jersey), Chicago (Illinois) and Sioux Falls (South Dakota) respectively. The capacity of production centres, the demand served by warehouses and the transportation cost (in USD per thousand HDDs) are given in the table below. The manufacturer wants to find how many HDDs should be supplied from each production center to each warehouse so as to minimize its transportation cost? Transport cost USD per 1000 from Sunnyvale from Dublin 1280 from Bangkok 1510 Demand (in 000s) 80 to to Amarillo Teaneck 260 420 990 1420 78 to to Chicago Sioux Fall 380 1440 1630 47 490 1520 1680 55 Capacity (in 000s) 45 120 95 a) Formulate the transportation problem of the manufacturer as an LP. Clearly mention what each variable and what each index represents. 5 marks b) Find the solution using MS-Excel solver. 5 marks c) Find a feasible solution to the transportation problem using Houtthaker's method. 3 marks d) Now find the optimal solution (obtained above) by using the Stepping Stone method. 7 marks