1. What is the effect of the size of the sample? In the X-bar chart, other things remaining the same, if the sample size increases, the length of the control interval (= UCL - LCL).
2. What is A standard survey instrument use to measure service quality.
3. The upper and lower control limits for sample means (samples of size 10) for a critical dimension of a product is 20.86 and 20.81 respectively. A new sample of ten items revealed a mean value of 20.87 meters. What should be the conclusion?