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: Machine Measurements #1 17 15 15 17 #2 16 25 18 25 #3 23 24 23 22 Using the factors for three sigma control limits, what are the sample range (R) chart upper and lower control limits? 11.88 and 0 9.88 and 0 12.88 and 0 10.88 and 0