Problem $778405$:

Do not include anything other than numbers in your responses. For example, do not include comma or dollar sign in your numbers. As a rule of thumb, keep $2$ decimal places for larger numbers and $3$ decimal places for smaller numbers less than $1.$

A small copy center uses approximately $26$ boxes of copy paper a week. Experience suggests that usage can be well approximated by a normal distribution with a standard deviation of $6$ box per week. $2$ weeks are required to fill an order for letterhead stationery. Ordering cost is $$3,$ and annual holding cost is $$0\mathrm{.}33$ per box. The manager's desired service level is $0\mathrm{.}7.$ Assume a year is $52$ weeks.