When constructing a u-chart,the standard deviation of each sample varies because the size of the sampling unit varies.

Question

Quizplus · Accepted Answer

In a u-chart, which is used for monitoring the number of defects per unit in a process, the standard deviation varies because it is dependent on the sample size, and in the case of a u-chart, the sample sizes (or the sizes of the sampling units) can vary. This variation in sample size directly affects the calculation of the standard deviation for each sample.

When Constructing a U-Chart,the Standard Deviation of Each Sample Varies