The company policy for customer service representatives gives time off for positive reviews. If, in the first 20 calls a customer service agent handles In a day, 13 or more elect to take a subsequent survey and rate the service as "excellent," then the company gives the agent his or her final hour of work that day off, paid. Ellie receives excellent reviews from about 30% of the calls she handles. Assuming she always receives at least 20 calls in the first 7 hours of a workday, on what percentage of her 8-hour workdays does Ellie get the final hour off?