Answer:
0.6
Step-by-step explanation:
Data provided :
Mean = 100
Standard deviation = 20
Salvage value of the tree = $ 0
Actual cost of the tree = $ 20
Selling cost of the trees = $ 50
Now, the cost of shortage = Selling cost - actual cost = $ 50 - $ 20 = $ 30
and the outrage cost = actual cost = $ 20
Now,
the service level is calculated as:
service level =

on substituting the value, we get
service level =

or
Service level = 0.6