T/F: (1 point each) 1. Common cause variation and special cause variation are actually the same thing 2. All processes contain a certain amount of variation in their output. 3. Data used for a P chart is attribute data. 4. Process control is achieved by taking periodic samples from a process and plotting the sample points on a chart to determine if the process is within control lmits. 5. Statistical process control involves monitoring and controlling a process to prevent poor quality. 6. The whole is equal to the sum of its parts 7. In a sysem, time delays between cause and effect can make it harder to make good decisions. 8. A positive feedback loop tends to be very stable over time. 9. Humans tend to easily manage in a complex system. 10. Deeper leverage points have greater potential, but are under-researched.

Problem (5 points) A company has been tracking the number of defects in a product it produces. Every hour, a sample of 50 items are inspected and the number of defects per sample are recorded. The results of the last 24 hours are shown to the right. 1. What is the standard deviation? 2. What is the UCL 3. What is the LCL 4. Is this system in or out of statistical control?

Sample Size = 50 # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Defects 8 14 7 11 7 14 11 10 10 10 12 7 6 8 11 6 6 7