Reconsider the diameter measurements in Exercise 15-7. Use the revised control limits and process estimates.

(a) Estimate PCR and PCR_k. Interpret these ratios.

(b) What percentage of defectives is being produced by this process?

Exercise 15-7

An extrusion die is used to produce aluminum rods. The diameter of the rods is a critical quality characteristic. The following table shows xÌ… and r values for 20 samples of five rods each. Specifications on the rods are 0.5035 ± 0.0010 inch. The values given are the last three digits of the measurement; that is, 34.2 is read as 0.50342.

Transcribed Image Text:

Sample 34.2 1 3 2 31.6 3 31.8 33.4 5 35.0 6. 32.1 2 32.6