A Quality Analyst wants to construct a control chart for determining whether three machines, all producing the same product, are under control with regard to a particular quality variable. Accordingly, he sampled four units of output from each machine, with the following results:

Part-A. A Quality Analyst wants to construct a control chart for determining whether three machines, all producing the same product, are under control with regard to a particular quality variable. Accordingly, he sampled four units of output from each machine, with the following results: [4 Marks Machine Measurements 17 15 15 17 #2 16 25 18 25 #3 23 24 23 22 #1 1A. What are the x-bar chart upper and lower control limits? [2.5 Marks] 2A. For upper and lower control limits of 23.29 and 16.71, which machine(s), if any, appear(s) to have an out-of-control process mean? [1 Marks] 3A. What are range chart upper and lower control limits? [1.5 Marks]