QUESTION $5$

Assume that The Washington Post $($WP$)$ operates a vertically integrated supply chain $($i$.$e$.,$ the WP produces and sells directly to the customers$).$ If the production cost of each paper is $$0\mathrm{.}2,$ the retail price is $$1$ and the demand is normally distributed with a mean of $550$ and standard deviation sigma $()=10$ then,

What is the optimal quantity of papers that WP should stock?

$416$ newspapers

$497$ newspapers

$507$ newspapers

$558$ newspapers

$624$ newspapers