Given that the overage cost is $$5$ and the shortage cost is $$4.$ What is the optimal order quantity based on a newsvendor model? The demand distribution is given in the table below.

Demand $150200250300400$

Probability $0\mathrm{.}30\mathrm{.}10\mathrm{.}20\mathrm{.}20\mathrm{.}2$

$150$

$200$

$250$

$300$

$400$