1. A company makes molded plastic toys. They study the plastic injection process into the molds. A common cause of variation is
A. the exact temperature of the injected plastic.
B. a new operator on the machine.
C. a new supplier of the raw plastic.
2. A company makes molded plastic toys. They study the plastic injection process into the molds. A special cause of variation is
A. the exact temperature of the injected plastic.
B. a small clog on the machine's injector ports.
C. a new supplier of the raw plastic.
3. A company makes molded plastic toys. They measure the hardness of the plastic after it cools for 5 minutes. The process has been in control with mean μ = 5.6 and standard deviation σ = 1.6. Each hour a sample of size 9 is taken for quality control. What are the control limits for an chart?
A. 5.07 to 6.13
B. 4 to 7.2
C. 4.55 to 6.65
4. A company makes molded plastic toys. They measure the hardness of the plastic after it cools for 5 minutes. The process has been in control with mean μ = 5.6 and standard deviation σ = 1.6. Each hour a sample of size 9 is taken for quality control. What are the control limits for an s chart?
A. 0.371 to 2.731
B. 1.299 to 9.229
C. 0.442 to 2.670