And you start with the first data point.

你从第一个数据点开始。

You start with the first data point, and you take the sum all the way to the n-th data point.

您从第一个数据点开始，一直求和到第 n 个数据点。

You start with the first data point, and you go all the way to the N-th data point, and you divide by N. You sum them all up and divide them by N. That's the mean.

你从第一个数据点开始，一直到第 N 个数据点， 然后除以 N。 你将它们全部相加并除以 N。 这就是平均值。