arithmetic mean

例句：

1. 1.The arithmetic mean of the numbers is 20.
   这些数字的算术平均值是20。
2. 2. The teacher asked us to calculate the arithmetic mean of the series.
   老师要求我们计算这个数列的算术平均值。
3. 3.The arithmetic mean of the population is 500,000.
   人口的算术平均值是50万。