Answer:
233 copies
Explanation:
Cost of shortage (Cs)= Revenue per unit - Cost per unit
Cost of shortage (Cs) = $12 - $8
Cost of shortage (Cs) = $4
Cost of excess (Ce) = Original cost per unit - Salvage value per unit
Cost of excess (Ce) = $8 - $0
Cost of excess (Ce) = $8
Service Level (SL) = Cs/(Cs+Ce)
Service Level (SL) = $4 / ($4+$8)
Service Level (SL) = $4/$12
Service Level (SL) = 0.33
Optimum Level = Minimum student + SL*(Maximum student - Minimum student)
Optimum Level = 200 + 0.33*(300 - 200)
Optimum Level = 200 + 33
Optimum Level = 233 copies