please solve using excel Solver Sensitivity

4.9 Leasing Warehouse Space: Cox Cable Company needs to lease warehouse be required in each month. However, since these space requirements are quite different, it may be economical to lease only the amount needed each month on a month-by-month basis. On the other hand, the monthly cost for leasing space storage space for 5 months at the start of the year. It knows how much space will for additional months is much less than for the first month, so it may be desire able to lease the maximum amount needed for the entire 5 months. Another option is the intermediate approach of changing the total amount of space leased (by adding a new lease and/or having an old lease expire) at least once but not every month. Two or more leases for different terms can begin at the same time. The space requirements (in square feet) and the leasing costs (in dollars per thousand square feet) are given in the two tables below. Month Requirements January 15,000 February March 10,000 20,000 April 5000 May 25,000 Lease length Lease cost 1 month 280 2 months 450 3 months 600 4 months 730 5 months 820 The task is to find a leasing schedule that provides the necessary amounts of space at the minimum cost. (a) Determine the optimal leasing schedule and the optimal total cost. (b) Consider what happens when the cost of a 5-month lease (currently $820 changes. Construct a graph showing how the optimal total cost varies with the cost of a 5-year lease, over the range from $800 to $1000. (e) Coneiden