4. Weekly demand for shampoo at a supermarket is normally distributed with a mean of 250 and a standard deviation of 2. The store manager continuously monitors inventory and currently orders 2*80 printers per order. The supply lead time is normally distributed with a mean of 2 weeks and a standard deviation of 1.5 weeks.

1. How much safety inventory should this store carry if it wants to provide a CSL of 95%?

2. How does the required safety inventory change as the standard deviation of lead time is reduced from 1.5 weeks to zero in intervals of 0.5 weeks?

3. What fill rate does the store achieve?