A manager in a call center needs to determine how many agents to schedule next week. Based on previous data, she expects to get $7940$ calls next week. The following conditions apply: On average $,$ call center agents can handle seven calls an hour. The call center is open for $10$ hours, $5$ days a week. Full time agents work $40$ hours per week. Full time agents work $40$ hours per week $,$ but are only on calls for $35$ hours a week. Part time agents work $20$ hours a week, but are only on calls $17$ hours per week. Which combination is the best to meet the scheduling needs?