The expected value of a positive integral power of a random variable . the first moment is the mean of the distribution 矩,动差任意变量的正整数功效的期望值。第一个矩是分配的平均数
4.
Development level of aviation industry of one country has been considered as a symbol of its technological standards and integral power of the country 航空工业的发展水平一直都是一个国家科技水平、综合国力的标志。