Answer:
31.58%
Step-by-step explanation:
We have the following information
Daily number = 120
Standard deviation = 15
Amount paid = 60 cents = 0.60dollars
What he gets for the unsold = 0.30 dollars
Undercoverage = Cu = 1.25-0.60 = 0.65
Over coverage = Co = 0.60 - 0.30 = 0.30
In stock probability = Cu/Cu + Co
= 0.65/0.65+0.30
= 0.65/0.95
= 0.6842
The optimal stocking out probability = 1- 0.6842
= 0.3158
= 31.58%