Question 18 4 pts A quality analyst wants to construct a control chart for determining whether three machines, all producing the same product, are in control with regard to a particular quality variable. Accordingly, he sampled four units of output from each machine, with the following results: Machine Observations #1 17 15 15 #2 1625 16 23 | 24 | 23 | 22 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? machine #3 machine #2 all of the machines none of the machines machine #1