Answer:
80%
Explanation:
In the question it is given that the shortage cost is 4 times the excess cost
So shortage cost =4 excess cost
The critical ratio or optimum service level is given by
[tex]C=\frac{shortage\ cost}{shortage\ cost+excess\ cost}[/tex]
So [tex]C=\frac{shortage\ cost}{shortage\ cost+0.25\ shortage cost}=\frac{1}{1.25}=0.8[/tex] =80%
So the optimum service level will be 80 %