Task:
A company produces and stocks computer printers in its finished-goods warehouse. These ‘demand during lead time’ (DDLT) historical data are believed to be representative of future demand for one printer model:
| Actual DDLT | Frequency | Actual DDLT | Frequency | 
| 0-29 | 0 | 70-79 | 0.25 | 
| 30-39 | 0.10 | 80-89 | 0.10 | 
| 40-49 | 0.10 | 90-99 | 0.05 | 
| 50-59 | 0.15 | 100-109 | 0.05 | 
| 60-69 | 0.20 | 110-120 | 0 | 
Calculate (a) the order point AND (b) the safety stock for EACH of the following scenarios:
1. If at least a 90% service level is to be provided for these printers.
2. If the DDLT for the printer is actually normally distributed with a mean of 65 and a standard deviation of 10, and a service level of 90% is to be provided for these printers.
3. If the lead time for these printers is so stable that the lead time can be assumed  to be a constant 6.5 days, the demand per day is normally distributed with a mean of 10 and a standard deviation of 2, and at least a service level of 90% is to be provided for these printers.