Please answer c$-$e$!$

Joe Birra needs to purchase malt for his micro$-$brew production. His supplier charges $$25$ per delivery $($no matter how much is delivered$)$ and $$1\mathrm{.}15$ per gallon. Joe's annual holding cost is $35\%$ of the price per gallon. Joe uses $200$ gallons of malt per week.

a$.$ Suppose Joe orders $125$ gallons each time. What is his average inventory?

$($Round your answer to $2$ decimal places.$)=62\mathrm{.}5$

b$.$ Suppose Joe orders $1250$ gallons each time. How many orders does he place with his supplier each year? $=8$ orders$/$yr

c$.$ How many gallons should Joe order from his supplier with each order to minimize the sum of ordering and holding costs?

$\_\_\_\_\_\_$ gallons

$($Round your answer to $3$ decimal places.$)$

d$.$ Suppose Joe orders $3000$ gallons each time he places an order with the supplier. What is the sum of ordering and holding costs per gallon?

$($Round your answer to $2$ decimal places.$)$

e$)$ Suppose Joe orders the quantity from part $($c$)$ that minimizes the sum of the ordering and holding costs each time he places an order with the supplier. What is the annual cost of the EOQ expressed as a percentage of the annual purchase cost?