Average demand $=30$ units per day

Average lead time $=40$ days

Item unit cost $=$$$45$ for orders of less than $400$ units

Item unit cost $=$$$40$ for orders of $400$ units or more

Ordering cost $=$$$50$

Inventory carrying cost $=15$ percent

The business year is $300$ days.

Standard deviation of demand during lead time $=90$

Desired service level $=95$ percent

What is the safety stock that HighLife Corporation should carry for its desired servi

$1\mathrm{.}28$ standard deviations cover $90$ percent

$1\mathrm{.}65$ standard deviations cover $95$ percent

$1\mathrm{.}96$ standard deviations cover $97\mathrm{.}5$ percent