In the unbalanced transportation problem in the table, if a unit from a source is not shipped out (to any of the destinations), a storage cost is incurred at the rate of S4, $5, and $3 per unit for sources 1, 2, and 3, respectively. Additionally, all the supply at source 1 must be shipped out completely to make room for a new product. 

i. Use least-cost's starting solution and determine all the iterations leading to the optimum shipping schedule. 

ii. Determine the range of values of c ₁₃  for which the current basis remains optimal.

4 5 40 20 3 30 30 20 20 1, 3. 3. 1, 2.