17-1. An extrusion die is used to produce aluminum rods. The diameter of the rods is a critical quality characteristic. Below are shown x and R values for 20 samples of five rods each. Specifications on the rods are 0.5035 t 0.0010 inch. The values given are the last three digits of the measurements; that is, 34.2 is read as 0.50342. a) Set up the X and R charts, revising the trial control limits if necessary, assuming assignable causes can be found (b) Calculate PCR and PCRe. Interpret these ratios. (c) What percentage of defectives is being produced by this process?