A hospital's biomedical repair shop uses a 4-week periodic system to maintain the inventory on the blood pressure cuff repair parts. They use an average 40 adult arm cuffs with a standard deviation of 6 cuffs during their reorder lead time. Cuffs aren't the most critical item they carry, but the manager would like to avoid the embarrassment of a stock out at least 95% of the time. What should their restocking level be