The overall length of a cigar lighter body used in an automobile application is controlled using control charts. The following table gives length for 20 samples of size 4 (measurements are coded from 5.00 mm; that is, 15 is 5.15 mm).
- Using Excel set up the appropriate control chart using these data.
- Estimate the process mean and standard deviation
- Does the overall length of the cigar lighter seem to be normally distributed?
- Specifications are 5.10 ± 0.05 mm. What can you say about the process capability?
- What fraction of cigar lighters is likely to be greater than the upper specification limit?
