A note on interval estimation of the standard deviation of a gamma population with applications to statistical quality control

作者：Frost Jaron; Keller Kara; Lowe Jonathan; Skeete Toya; Walton Shonte; Castille Jessie; Pal Nabendu^*

来源：Applied Mathematical Modelling, 2013, 37(4): 2580-2587.

DOI：10.1016/j.apm.2012.05.027

• Sample variance
• Standard deviation
• Interval estimation
• Confidence level
• Gamma distribution
• Upper control limit

Traditional process control charts for a measurement standard deviation are based on the assumption of normality, which may not always be valid. Assuming that measurements follow a gamma distribution, we have obtained an approximate distribution of the sample variance, scaled appropriately. This approximate distribution, which happens to be another gamma model, is used to derive an interval estimate of the population standard deviation. Further, the above approximate gamma model for the sample variance can be used to develop a process control chart as demonstrated by a simulated data set.

• 出版日期2013-2-15