You're a manager of a hotel. You want to achieve the higest level of service. For 7 days, you collect data on the readiness of 200 rooms. Day #Rooms #Not Ready 1 200 26 2 200 30 3 200 20 4 200 28 5 200 30 6 200 38 7 200 38 Total: 210 The p control chart is to be made for these data. The proportion p (the center line) is