Populations, random samples. Sample statistics, moments of the sample mean and variance.
母体， 随机样本。 样本统计， 样本平均数和变异数的动差。
2
Demonstrate understanding of the concept and properties of a discrete random variable, including calculation and interpretation of the mean and variance.
示范不连续任意的变数观念和财产的理解，包括计算和解释那低劣的和不一致。
3
First, we standardized the size, varianceof gray scale and mean value of gray scale of the motor vehicle plate images.