Caring Hospital’s dispensary reorders doses of a drug when the supply on hand falls to 18 units. Lead time for resupply is three days. Given the typical usage over the last 10 days, what service level is achieved with the hospital’s reorder policy? (Hint: Use the following formula.) (Do not round intermediate calculations. Round your "z" value and final answer to 2 decimal places. Omit the "%" sign in your response.)