Answer:
The unit=9
Step-by-step explanation:
The Cost of underage Cu= price -cost =200-0 =200 ( as there is no variable cost of the unsold room)
Cost of overage Co= cost - salvage value = 0 -(-325) =325
Service level = Cu / Cu+Co = 200/ 325+200 = 0.3809
which corresponds to the z value of -0.3
the optimum overbooking = mean + z x SD
= 10+ 3 x (-0.3) =9