1. The population mean and standard deviation for a process for which we have a substantial history are 120 and 4.21, respectively. For the variable control chart, a sample size of 16 will be used. What is the standard deviation of the sampling distribution?
2. The population mean and standard deviation for a process for which we have a substantial history are 120 and 14.01, respectively. For the variable control chart, a sample size of 16 will be used. What is the three-sigma upper control limit for the process?
3. The population mean and standard deviation for a process for which we have a substantial history are 120 and 3.45, respectively. For the variable control chart, a sample size of 16 will be used. What is the three-sigma lower control limit for the process?