Network flow question

Allware company needs to find a minimum cost transportation plan. Three warehouses (A,B and C ) are supplying products to four customers (X,Y,Z and W). Supplies at A,B and C are 25,40 and 50 respectively. Demands at X,Y,Z and W are 17,38,30 and 30 respectively. Transportation costs from warehouses to customers are given in the table below. a) Find an initial feasible solution using Vogel's approximation. b) Find an initial feasible solution using North West Corner method. c) Determine if the initial feasible solution you found at part b is optimal. If the solution is not optimal, obtain an improved solution. Use Stepping Stone Algorithm. Show your work