The current order quantity for Electric Powerbars is $100$ bars. The order cost is $$10$ per order, the holding cost is $$0\mathrm{.}25$ per bar per year, and the annual demand is $2,000$ bars per year.

a$.$ Calculate the annual holding cost plus the annual ordering cost to get the total annual cost when using an order quantity of $100$ bars.

b$.$ Calculate the EOQ and the total annual cost for this order quantity.

c$.$ How many orders per year are necessary when $Q=100?$ How many orders per year are necessary for the EOQ in part $b?$

d$.$ Graph the annual inventory cost $($IC$)$ using MS Excel. Show the holding cost, ordering cost, and total inventory cost as a function of order size $Q.$