For a four$-$month inventory problem, the demand and cost data for each month are provided in

the following table The products are produced in batches of $5$ The initial inventory available at the

beginning of the first month is $5$ units and it is desired to have $5$ units at the end of the $4^{th}$ month.

a$.$ Use dynamic programming to find the optimal policy and minimum total cost $($use backward

recursion$).$

b$.$ Find the optimal policy by using dynamic programming in EXCEL $($Hint: It is very similar to the

shortest path DP Excel solution. But you need to find a way to add costs$).$

Could you please solve and explain the second option or solve it in a clear way so that I can understand the whole question?