Q$2)$ The KFU's Company is currently operating its mill six days a week, $24$ hours a day, on three shifts. At current prices, the company could easily obtain a sufficient volume of sales to take the entire output of a seventh day of operation each week. The mill's practical capacity is $7,000$ hundred weight of flour per day. Note that $*$ Flour sells for SAR $13$ a hundred weight $($cwt$.)$ and the price of wheat is SAR $5\mathrm{.}0$ a bushel. About $2\mathrm{.}35$ bushels of wheat are required per cwt$.$ of flour. Fixed costs now average SAR $5,530$ a day, or SAR $0\mathrm{.}79$ per cwt$.$ The average variable cost of mill operation, almost entirely wages, is SAR $0\mathrm{.}5$ per cwt$.*$With Sunday operation, wages would be doubled for Sunday work, which would bring the variable cost of Sunday operation to SAR $0\mathrm{.}9$ per cwt$.$ Total fixed costs per week would increase by SAR $500($or SAR $33,333)$ if the mill were to operate on Sunday.

$($a$)$ Using the information provided, compute the break$-$even volumes for sixday and sevenday operation.

$($b$)$ What are the marginal contribution rates for six$-$day and seven$-$day operation?

$($c$)$ Compute the average total cost per cwt$.$ for six$-$day operation and the net profit margin per cwt$.$ before taxes.

$($d$)$ Would it be economical for the mill to operate on Sundays?