QUESTION 22 In an Xbar-R chart how many subgroups are needed for enough data to calculate initial control limits ? 1.10 2.25 3.50 4.75 QUESTION 23 In an Xbar-R control chart, what is the chance of being wrong when a point is called a special cause outside the 3 sigma limit? 1. About 50%. 2. About 25%. 3. About 5%. 4. About 1%. QUESTION 24 In six sigma problem solving, what actions are always completed first ? 1. Visiting the supplier. 2. Developing team consensus regarding the exact nature of the problem. 3. Initiate actions to fix the problem. 4. Implement corrective actions