Through analyzing the dangerous trends of these enterprises with sample mean value and coefficient of variation of standard deviation,it was.

Analysis on how to influence the standard deviation coefficient by utilizing the unit contribution margin;

Based on this result, the relationship between the Gini coefficient of some distribution and the standard deviation coefficient was discussed, also a method for discussing for general distributions function the Gini coefficient was given, i.

In the paper,we discuss some questions about indices of characteristic variation in statistics such as standard deviation,simple method of standard deviation and coefficient of standard deviation.

The growth rates of the earning per share and the sales have the same coefficient of standard deviation, indicating that the leverage doesn t change the growth rates of the business relative risk.

By applying multiple central limit theorem,it′s proved that difference of variation coefficient of two normal distribution is asymotic normality.

Recently, the exports of China\'s chemical products have grown rapidly, while they have been hampered severely for standard differences, especially when the REACH regulation has been put into practice by EU in June, 2007.